Spinal Vascular Malformations

Spinal vascular malformations consist of an abnormal connection between the normal arterial and venous pathways. These malformations do not benefit from intervening capillaries. As a result, venous pressure increases and the individual is predisposed to ischemia or haemorrhage.


The vascular lesions of the spinal cord are usually uncommon and may present with the progressive weakness. The spinal cord compression may be due to mass effect of the lesion expansion or  haemorrhage or venous congestion.
Usually the initial investigation for any spinal cord lesion presenting with weakness of limbs is MRI of the spine. MRI may diagnose many lesions. But gold standard investigation for the diagnosis of vascular malformation of spine is spinal angiography.

3 common types of spinal vascular malformations are:

1. Cavernous malformations or Cavernous angiomas or Cavernomas
2. Arteriovenous malformations
3. Arteriovenous fistulas




Cavernous malformations are also known as cavernous angiomas or cavernomas. They constitute about 5% to 12% os spinal vascular malformations. They are aniographically occult , i.e., they may not be seen on angiography. They become symptomatic due to mass effect or due to haemorrhage. They are prone to repeated haemorrhage. So on MRI of the spine a mass occupying lesion may be seen inside the spinal cord hich is surrounded by a gliotic, hemosiderin rim. Patient may present with features of myelopathy due to recuuring hemorrhagic episodes.
Characteristics of intracerebral, brain stem and spinal cavernomas are almost similar.
So, here I have emphasized to describe spinal AVF & spinal AVM in detail.

About a century ago, In 1914, Charles Elsberg performed the first successful operation on a spinal cord malformation. In 1960s, Kendall and Loque used techniques of spinal angiography to define spinal AVMs . In 1977, Kendall and Loque treated these lesions with the less-invasive technique of directly ligating the fistula origin along the dural sleeve, with good results [Kendall].


 Many ways have been proposed to describe and classify these vascular lesions of the spinal cord. But, my aim is to provide a simple yet comprehensive view of these lesions so that any neurosurgical trainee can comprehend the entire subject.

In 1992, Anson and Spetzler classified spinal cord vascular malformations into the following 4 categories:

Type 1: This dural AVF is the most common type of malformation, accounting for 70% of all spinal vascular malformations [Patsalides et al ]. These fistulas are created when a radiculomeningeal artery feeds directly into a radicular vein, usually near the spinal nerve root. Dural AVFs are most commonly found in the thoracolumbar region [ Krings]. Patients with type 1 malformations become symptomatic because the AVF creates venous congestion and hypertension, resulting in hypoperfusion, hypoxia, and edema of the spinal cord. Due to the slow-flow nature of type 1 AVFs, hemorrhage rarely occurs. Most dural AVFs are believed to occur spontaneously, but the exact etiology is still unknown [Krings].

Type I lesions are most frequently found in men between the fifth and eighth decades of life and patients with AVFs are typically older than 40 years. Symptoms increase over an extended period of months to years and include progressive weakness of the legs and concurrent bowel or bladder difficulties. Typically, pain is located in the distal posterior thoracic region over the spine, without a significant radicular component. However, painful radiculopathy may be present. Activity or a change in position may exacerbate symptoms in the thoracic or lumbar region and can result in thoracic spinal cord venous congestion and lower-extremity weakness.

These lesions can be mistakenly diagnosed as spinal stenosis and neurogenic claudication. Foix-Alajouanine syndrome is an extreme form of spinal dural AVF that affects a minority of patients. These patients present with a rapidly progressive myelopathy due to venous thrombosis from spinal venous stasis.

Type 2: ( also referred to as a glomus AVM or racemosum ) type 2 malformations are high flow lesions located within the spinal cord. This Glomus AVM consists of a tightly compacted group of arterial and venous vessels (nidus) inside a short segment of the spinal cord. Multiple feeding vessels from the anterior spinal artery and/or the posterior spinal circulation typically supply these AVMs. The abnormal vessels are intramedullary in location, although superficial nidus compartments can reach the subarachnoid space [Krings]. Type 2 AVMs are the most commonly encountered intramedullary vascular malformations, representing about 20% of all spinal vascular malformations. These lesions usually present in younger patients with acute neurologic deterioration secondary to their location, which is usually the dorsal cervicomedullary region. The mortality rate related to type 2 malformation is reported at 17.6%. After initial hemorrhage, the rebleed rate is 10% within the first month and 40% within the first year.

Type 3: These malformations are arteriovenous abnormalities of the spinal cord parenchyma fed by multiple vessels. These juvenile malformations are extensive lesions with abnormal vessels that can be both intramedullary and extramedullary in location. These lesions are typically found in young adults and children.

Type 4: Also known as pial AVFs, these malformations are intradural extramedullary AVFs on the surface of the cord that result from a direct communication between a spinal artery and a spinal vein without an interposed vascular network. They are usually seen in patients who are between their third and sixth decade of life.

Spinal malformations can also broadly be separated into 2 subgroups. Spinal vascular malformations can also be classified into 2 general groups. One group consists of the spinal dural fistulas (type 1), and the other group has intradural pathology (types 2-4).


Investigations
CT scanning may demonstrate dilated vessels in the thecal sac, but findings are usually normal. If a patient presents with symptoms of subarachnoid hemorrhage, CT scanning demonstrates blood in the spinal fluid.


Myelography findings, with or without CT, show dilated vessels in the intradural space. This imaging modality is very sensitive and shows these abnormalities in detail. This is an invasive procedure that requires injection of a contrast agent into the thecal sac. Postprocedure headaches are not uncommon.


MRI is a noninvasive imaging modality. The soft tissue and neural elements are visualized in detail with this technique. Dilated intradural vessels can be seen as flow voids or can be seen filling with contrast. Edema or hemorrhage in the spinal cord parenchyma can be assessed. The exact fistula site cannot be localized.


MRI of dural AVFs on the thoracolumbar junction usually shows serpiginous vessels in the intradural compartment, along with vasogenic edema in the spinal cord. Intradural vascular spinal malformations appear as lesions in the spinal parenchyma.


MRA or CTA are noninvasive modalities being used to identify any abnormal vessels. However, the resolution of these modalities is not to yet high enough.


Arteriography is the gold standard modality for visualizing arteriovenous malformations (AVMs). This is a dynamic study that allows visualization of the pathology in real time, allowing assessment of high-flow versus low-flow AVMs. In addition, the location of the fistula can be visualized. Arteriography is an invasive procedure that may cause morbidity such as spinal cord ischemia, cerebral vascular accident, and vascular dissection.


Spinal MRI is first-line screening method to detect spinal vascular malformations. If a spinal vascular malformation is still suspected, digital subtraction angiography (DSA) must be performed to display the very small vessels of the spinal cord. As DSA is an invasive procedure, an MR angiography (MRA) or CT angiography (CTA) can be used to determine the spinal cord level of the feeding artery.

Treatment of SVMs
The ideal treatment of spinal vascular malformation is to obliterate the nidus without damaging the spinal vascular blood supply and spinal cord. It may be achieved with open surgery, endovascular methods, or a combination of both. Stereotactic radiosurgery is a newer modality of treatment.

The present surgical treatment options include open surgical ligation or resection of the malformation, endovascular occlusion, spinal radiation, or a combination of these techniques.

Surgical excision is the mainstay of treatment of cavernomas.

Dural arteriovenous fistulas (AVFs), type 1, can be treated with either open or endovascular ligation. Both techniques yield excellent results, with occlusion rates reported as higher than 80%. The benefit of the endovascular technique is that it is less invasive. If the patient has multiple sites of fistula formation, open ligation is more appropriate because all feeding vessels may be ligated under direct vision. Open surgery is necessary if the arterial feeding vessel is impossible to access because of tortuous vascular anatomy or if the vessel supplies blood to healthy regions of the spinal cord [Özkan, Lin, Signorelli, Clark, Kirsch, Maimon]

Intradural AVMs (types 2-4) are typically best treated with endovascular surgery and, if required, open surgery and resection.

Treatment options are dictated by the location of the lesion, the patient's medical condition, and the risk-versus-benefit ratio. The most important factor in determining treatment options is the presence of intramedullary or extramedullary shunting. Malformations that are subpial in location are less likely to be cured. These are usually supplied by subcommissural branches of the anterior spinal artery (ASA). Lesions on the surface of the spinal cord that are supplied by circumferential branches of the ASA may be safely treated with either embolization or surgery.


The new generation of liquid embolic material and microcatheters has made interventional treatment of spinal AVMs safer, with better results [Warakaulle , Corkill].The goal of any intervention is to eliminate the shunt. Microcatheterization is of paramount necessity in achieving effective results. Delivery of embolic material to the nidus of the lesion reduces the arteriovenous malformation (AVM) and reduces the risk of inadvertent embolization of normal vessels.


When preoperative embolization is planned, polyvinyl alcohol microparticles (PVAs) are a reasonable choice of embolic material. They are also useful for embolization of type 2 AVMs. The advantages of PVA are that embolization may be performed at a more proximal location and that the size of particle can be determined depending on the size of the lesion and its collaterals. The goal of treatment with either agent is to provide distal occlusion of the nidus. Proximal occlusion results in collateral reconstitution, with little hope of cure.


Procedure is done under general anesthesia and neurophysiologic monitoring. Somatosensory-evoked potentials (SSEPs) help in assessing spinal cord function. Motor-evoked potentials (MEPs) are also useful when a spinal AVM is supplied by the ASA.





References

1. Harrop JS. Vascular malformations of the spinal cord.
                  http://emedicine.medscape.com/article/248456-overview
2. Anson JA, Spetzler RF. Interventional neuroradiology for spinal pathology. Clin Neurosurg. 1992. 39:388-417.
3. Patsalides A, Santillan A, Knopman J, et al. Endovascular management of spinal dural arteriovenous fistulas. J NeuroIntervent Surg. 2010. 3(1):80-84.
4. Krings T. Vascular Malformations of the Spine and Spinal Cord : Anatomy, Classification, Treatment. Klin Neuroradiol. 2010 Feb 28.
5. Özkan N, Kreitschmann-Andermahr I, Goerike SL, Wrede KH, Kleist B, Stein KP, et al. Single center experience with treatment of spinal dural arteriovenous fistulas. Neurosurg Rev. 2015 Oct. 38 (4):683-92.
6. Kendall BE, Loque V. Spinal epidural angiomatous malformations draining into intrathecal veins. Neuroradiology. 1977. 13:181-189.
7. Aadland TD, Thielen KR, Kaufmann TJ, et al. 3D C-arm conebeam CT angiography as an adjunct in the precise anatomic characterization of spinal dural arteriovenous fistulas. AJNR Am J Neuroradiol. 2010 Mar. 31(3):476-80.
8. Lin N, Smith ER, Scott RM, Orbach DB. Safety of neuroangiography and embolization in children: complication analysis of 697 consecutive procedures in 394 patients. J Neurosurg Pediatr. 2015 Oct. 16 (4):432-8.
9. Signorelli F, Della Pepa GM, Sabatino G, Marchese E, Maira G, Puca A, et al. Diagnosis and management of dural arteriovenous fistulas: a 10 years single-center experience. Clin Neurol Neurosurg. 2015 Jan. 128:123-9.
10. Clark S, Powell G, Kandasamy J, Lee M, Nahser H, Pigott T. Spinal dural arteriovenous fistulas--presentation, management and outcome in a single neurosurgical institution. Br J Neurosurg. 2013 Aug. 27 (4):465-70.
11. Kirsch M, Berg-Dammer E, Musahl C, Bäzner H, Kühne D, Henkes H. Endovascular management of spinal dural arteriovenous fistulas in 78 patients. Neuroradiology. 2013 Feb. 55 (3):337-43.
12. Warakaulle DR, Aviv RI, Niemann D, Molyneux AJ, Byrne JV, Teddy P. Embolisation of spinal dural arteriovenous fistulae with Onyx. Neuroradiology. 2003 Feb. 45(2):110-2.
13. Corkill RA, Mitsos AP, Molyneux AJ. Embolization of spinal intramedullary arteriovenous malformations using the liquid embolic agent, Onyx: a single-center experience in a series of 17 patients. J Neurosurg Spine. 2007 Nov. 7(5):478-85.
14. Veznedaroglu E, Nelson PK, Jabbour PM, Rosenwasser RH. Endovascular treatment of spinal cord arteriovenous malformations. Neurosurgery. 2006 Nov. 59(5 Suppl 3):S202-9; discussion S3-13.
15. Schuette AJ, Cawley CM, Barrow DL. Indocyanine green videoangiography in the management of dural arteriovenous fistulae. Neurosurgery. 2010 Sep. 67(3):658-62; discussion 662.
16. Bridwell KH, DeWald RL. The textbook of Spinal Surgery , 3rd ed. ( Wolters Kluwer/ Lippincott, Williams & Wilkins, 2011.

Clinical Audit

Clinical audit is audit or review of the clinical care. 

Clinical audit work may be equated with the work of CA ( Chartered Accountant) in finance & accounts for example a Chartered accountant audits the accounts and finance according to the standards and financial rules, Similarly clinical audit is regarded as an important component of the “Clinical Governance”. Clinical audit is in practice in many countries but NHS in UK stresses on it and there is Clinical Audit Guidance Group in NHS in United Kingdom.

Clinical audit  aims to improve the clinical care of the patients.

Many descriptions are available online but the most relevant definition of Clinical Audit is given by National Institute of Clinical Excellance, UK in “ Principles of Best practice in Clinical audit”, NICE,2002.  

“ A quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit standards and implementation of change”

The objectives of Clinical audit is to identify, compare the current quality of care of patients with established protocols of best evidence based clinical practice and then implement the required and necessary changes. Then re-audit is done to assess the improvement in patient outcome as a result of implementation of changes in clinical practice. This completes one cycle of the clinical audit.

Clinical audit ensures best possible care of patients according to the evidence based clinical practice and efficient use of resources.. It helps to improve multidisciplinary team work .  The clinical audit should be patient centric and should have positive impact over clinical outcome.


Anything relevant to patient care may be audited whether structural, procedural or outcome of any intervention.


It begins with selection of a topic and defining the objective of clinical audit. Then select standards followed by collected of data. Then the next step is analysis of the data and making recommendation. The last step is to implement the changes and reaudit.


Clinical audit should be impartial, pro active and involves team members who are concerned with patient care and wish to improve.

Not doing clinical audit indicated that you do not want or you do not know the impartial mechanism to improve . It is like playing a sport without a scoring board and without a system of reviewing our own or team's performance. So you keep on repeating the same mistakes and ignoring the areas where you or your team could improve. It is not a fault finding or punitive exercise But, the findings of clinical audit should be shared so that other team members also improvise.

The earliest contributions to the concept of clinical audit is contributed to Florence Nightingale ( 1820-1910) who worked during the Crimean war in Medical barracks Hospital in Scutari in 1854 and led a team of 38 nurses. She improved the care of the wounded persons and found that by improving the sanitation, cleanliness mortality was reduced from 40% to just 2%.

Later Ernst Codman ( 1869-1940) introduced the concept of Monitoring Surgical outcomes " end result idea" and he is regarded as Medical auditor.

Resources
Wikipedia, NICE guidelines, NHS, Journal of Clinical Audits ( www.clinicalaudits.com),

Health Quotient ( HQ )

I wish to coin a new term "Health Quotient."  It will denote the relative well being and health of a person as compared to the health of a normal person of that particular age. As IQ is of relevance in younger age group , this term HQ will be of particular value in people of older age groups.
Assessment of health quotient includes intelligence, memory, locomotor strength & physical well being, any co-mobidity or disability, activity of daily living, physical and emotional independence, interest & motivation. For example a 40 year person is expected to have normal locomotor activity, normal hearing and a good respiratory function but a diseased person may have poor cardiac and respiratory reserve due to chronic smoking, alcoholism, sedentary life style. So, the health quotient may a good marker of socio-economic productivity of a person.
This quotient is of immense value in present time because of increased life expectancy and better health of people even after the retirement age. The age old norms of retirement age are becoming irrelevant because people are healthy and eager to continue wor even after fficial retirement age. In some professions, in fact, people gain maturity and wisdom with time. Many physicians, entrepreneuers, politicians, businessmen are well respected and active when they surpass the age of retirement.
So, there should be an objective criteria to evaluate the health quotient of a person and he or she should be asked to continue active contribution to the society.

Brain App

The human brain is truly astonishing structure and is probably most complex thing in the universe. Our brain constitutes 2 percent of our body weight, but inside the brain are approximately 86 billion neurons, surrounded by 180,000 kilometers of insulated fires connected at 100 trillion synapses. It is like vast supercomputer. The neurons communicate using electrical signals. Brain is an amazing structure which creates interest in people of all age groups. It is very interesting that a tiny brain of small animals can perform almost all activities necessary to sustain life. Human brain is about 1200 grams to 1500 grams in weight. But if there is damage to the brain in neurotrauma or in stroke or birth anoxia, even a large part of the remaining brain is unable to help a person to perform all activities.
So, in small creatures like ants a tiny brain is self sufficient but in an adult person with about 1 Kilogram of injured brain becomes severely impaired. Therefore, a large brain of a patient of brain disease cannot perform all functions.
It may be possible that brain of an ant may be like a brain app which may be having a limited but complete set of basic applications necessary for a normal person. It may be possible that a new born ant may be born with this app but a newborn infant of human beings may not be able to take care of themselves due to lack of this app in the brain of human beings.
Speculations of a brain app needs to be explored.
A further research in this area may help a lot of newborns with cerebral palsy or birth anoxia. As these children have almost normal sized brain but are unable to perform even normal daily life activities independently.
Although human brain has infinite potential but takes lot of time to become mature but is also vulnerable to injuries during the process of development. Neuronal Plasticity allows other parts of brain to takeover the function of the injured part, but there is need to identify an app in the brain which may be very small , transplantable or amenable to modifications.
Although, a lot of research has been done in other fields but the clinical applications of such research will benefit millions of patients suffering from stroke, cerebral palsy, birth anoxia, Alzheimer's disease and other neurodegenerative disorders.
Technological advancements in artificial intelligenc, robotics, bionics, etc, may be replicated in neurosciences to find solutions to brain deficits. 

Chondrosarcoma of spine

Chondrosarcomas are malignant cartilage forming tumors. Chondrosarcoma is the second most common primary tumor of the spine after multiple myeloma.  

Chondrosarcoma may be classified as primary ( arising de novo) or secondary ( arising from a pre-existing osteochondroma or enchondroma).

Although chondrosarcoma is second most common primary malignat tumor of the bone but chondrosarcoma of spine is uncommon. It rarely grows inside the spinal canal [ Arockiaraj et al, 2012].

Chondrosarcomas arising from the vertebral axis usually present as slowly growing mass with an insidious onset, associated with pain and local tenderness, usually associated with neurological deficits at the time of presentation.

Chondrosarcomas usually appear as osteolytic lesions with endosteal scalloping and cartilaginous matrix calcifications. Punctate , pop-corn like calcifications , arcs and ring types have been described for matrix mineralization which is pathognomonic for chondrosarcoma.

Chondrosarcomas of the spine usually belong to the mesenchymal or clear cell histological types.

The ideal treatment consists of total “en-bloc” resection, not always achievable due to limitation of location, compromise of stability and risk of inducing neurological deficits.

References:

Justin Arockiaraj, Krishnan Venkatesh, Rohit Amritanand, Gabriel David Sundararaj, Gurusamy Nachimuthu.  Chondrosarcoma of the Spinous Process: A Rare Presentation. Asian Spine Journal Vol. 6, No. 4, pp 279~283, 2 012

C. Ruivo, Hopper. Spinal chondrosarcoma arising from a solitary lumbar osteochondroma, JBR–BTR, 2014, 97: 21-24.

 

Daniel Monte-Serrat Prevedello, Joacir Graciolli Cordeiro, Andrei Koerbel, Léo Fernando da Silva Ditzel, João Cândido Araújo. Management of primary spinal Chondrosarcoma.Report of two cases causing cord compression . Arq Neuropsiquiatr 2004;62(3-B):875-878

 

Ratliff J, Voorhies R. Osteochondroma of the C5 lamina with cord compression: case report and review of the literature. Spine (Phila Pa 1976). 2000 May 15;25(10):1293-5.

 

Nick Vertzyas, John Cummine, Sandra Biankin and Michael Bilows. Chondrosarcoma of the thoracic spine in an 8-year-old child with 12 years follow-up: A case report. Journal of Orthopaedic Surgery 2000, 8(1): 89–92.

Osteoblastoma of Spine

In 1935 Jaffe described a new bone lesion , which he named osteoid osteoma.  In 1956, Jaffe and Lichenstein independently proposed the term “ benign osteoblastoma”. Osteoid osteoma and osteoblastoma are bone producing lesions that are frequently localized in long bones and posterior elements of the vertebra^1-5.

Primary osseous tumors of the spine are uncommon  lesions that are much less frequently encountered than metastases, multiple myeloma, and lymphoma⁴. Osteoid osteoma (OO) and osteoblastoma ( OB) are rare primary bone tumors that usually do not arise in the spine⁴.

Benign osteoblastoma is a very rare lesion presenting 1 percent of all primary bone tumors. Osteoblastoma is histologically similar to osteoid osteoma, but Osteoblastoma  occurs in slightly older patients, has a greater propensity for the spine and more aggressive , often eroding through spinal cortical bone and creating large soft tissue masses. Some distinguish the two based on size with lesions less than 1.5 cm classified as Osteoid Osteoma , and those larger than 1.5 cm are considered Osteoblastoma^6,7. Moreover, Osteoblastoma  of the spine may have soft tissue masses, which initially may encroach on the spinal canal and later may surround the dural sac or adjacent nerve roots or both⁴. Osteoblastomas  occur predominantly in patients younger than 20 years of age. Clinically, the pain of Osteoblastoma is not as severe at night, nor is it relieved by aspirin or NSAIDs , as is the pain of Osteoid Osteoma. Unlike osteoid osteoma no spontaneous regression has been reported with osteoblastoma⁸.

When these lesions occur in the spine,  common manifestations are pain, scoliosis and neurological involvement^4,9.  The primary histologic difference between Osteoid Osteoma & Osteoblastoma is the tendency of OB to form a less sclerotic but more expansile mass. The nidus characteristic of OO is not found in OB. Also, large vascular spaces seen in OB are rare in OO⁴.

On histological examination osteoid osteoma consists of small yellowish to red nidus of the osteoid and woven bonewith interconnected trabeculae, and a background and rim of highly vascularised fibrous connective tissue. Varying degrees of sclerotic bone reaction may surround the lesion⁴.

Benign osteoblastoma is virtually indistinguishable from osteoid osteoma. The usual appearance included a fibrovascular stroma with numerous osteoblasts, osteoid tissue, well formed woven bone, and giant cells.⁴. Osteoblastomas have an abundantly vascularised stroma containing a great number of very active osteoblasts ( creating osteoid and primitive osseous trabeculae with somewhat more regular orientation). Osteoblasts are usually larger with atypical nuclei and more frequent and somewhat pathological mitoses. Mineralization of bone trabeculae is uneven and irregular, osteoblasts are numerous especially around the zones of hemorrhage⁵.

In a histological aggressive osteoblastoma bone trabeculae are broad and irregular. The deposited osteoid is usually stacked in layers ( lamelated) but not trabeculated. Swollen, enlarged osteoblasts coating trabeculae or osteoid are a typical feature. The stroma is fibrous, made of spindle cells, with an increased cellularity and focus whirling cellular agglomerations⁵.

Patients of osteoblastoma usually present with back pain. Patients may also present with progressive focal or radicular pain exacerbated by movement. The other common symptom is stiffness. The  time from onset of symptoms to diagnosis is typically several months because it is rare entity and radiographic studies are often negative early in the course of the disease⁶. Many patients will progress to manifest neurological sequelae or a painful scoliosis⁶.

 The plain x-ray, CT scan and MRI aid in the diagnosis. Radigraphically the tumor is often radiolucent. On x-rays osteoid osteomas are usually about 2 cm size with a sclerotic rim and osteoblastomas are usually  larger in size. Both osteoid osteoma and osteoblastomas are more common in posterior elements occurring predominantly in the pedicles, transverse processes, lamina and spinous processes. Osteoblastomas may have soft tissue masses, which initially may  encroach on the spinal canal and later may surround the dural sac or adjacent nerve roots, or both⁴. Extent of the osseous involvement is assessed by x-ray and CT scan of the spine. MRI reveals the nidus,  intra- and extraosseous reactive changes and the possible infiltration of adjeacent soft tissues. MRI is the best to show the effects of the tumor on the spinal canal and cord⁴.

Technitium bone scanning may accurately localize the lesion as it demonstrates an intense focal accumulation of the bone seeking agent. The site of the tumor appears as a typical “ hot spot” on a technetium bone scan.But, if lesion is already discernible on x-ray films, the scintigram is unnecessary⁴.

Surgery is the most common treatment for this disease, and prognosis after total resction is favourable.The recommended treatment is excision. Most OB are multilobular with extension into the  paraspinal mass may not allow en bloc resections. Recurrence is the result of incomplete resection . these lesions hardly ever undergo malignat transformation into osteosarcoma and metastasize. Differentiation between these tumor and fibrous dysplasia , osteosarcoma, giant cell bone tumor, or aneurismal bone cyst is necessary which usually have different radiology and histology⁴.

Lesions may be  well-circumscribed margins confined within the vertebral structure (Enneking Stage 2), or ill-defined margins with soft-tissue extension (Enneking Stage 3). The staging system for benign musculoskeletal tumors based on radiographic characteristics consists of three categories: ie, latent, active, and aggressive. Latent means lesions with well demarcated borders, active lesions have indistinct borders and aggressive lesions reveal indistinct borders on radiography. Well-defined lesions are treated with curettage, with excellent results. The more extensive lesions are treated by intralesional excision and adjuvant radiation therapy^10,11.  

So, the well-defined lesions are excised or removed completely with curettage. The more extensive lesions were treated by intralesional excision and adjuvant radiation therapy⁹.

There are few data about the effectiveness of chemotherapy or radiotherapy in the treatment of recurrent osteoblastoma. Surgery remains the treatment of choice for osteoblastoma. Radiotherapy and chemotherapy either alone or together may be useful in selected patients with recurrent, aggressive tumor or in patients with surgically unresectable disease¹².

Resection of the tumor may be done either through the anterior approach or posterior approach depending upon the location of the tumor in the vertebra. Surgical approaches, bone grafting , implants and spinal fixation may also vary depending upon the site of the lesion in vertebral column.

So, to achieve the safe resection many studies have been published in English literature, highlighting the modern technologies and multimodality approaches. Samsadi et al proposed the preoperative angiography to confirm hypervascularity of the lesion and consequent embolization and resection⁶.

The resection of the abnormal pedicle, transverse process, pedicle and facet joint may lead to instability of the spine and requires spinal stabilization with instrumentation.Video assisted thoracoscopic surgery (VATS)  and  Video assisted thoracoscopic surgery guided by a navigation system ( VATS-NAV) allows accurate localization and guidance for complete excision of a spinal osteoid osteoma through a minimally invasive approach without compromising spinal stability¹³.

An underlying osteoid osteoma and osteoblastoma must be suspected in all young patients presenting with pain, painful scoliosis and stiffness. Early diagnosis is possible with x-ray, CT scan, MRI and technetium bone scan. Early diagnosis and treatments prevents scoliosis & permits complete resection without jeopardizing the stability of the spine¹⁴.

 

References

1. Jaffe HL, Mayer L. An osteoblastic osteoid tissue-forming tumor of a metacarpal bone. Arch Surg. 1932;24:550–564.
2. Jaffe HL. Benign osteoblastoma. Bull Hosp Joint Dis. 1956;17:141–151
3. Lichtenstein L. Benign osteoblastoma : a category of osteoid- and bone-forming tumors other than classical osteoid osteoma, which may be mistaken for giant-cell tumor or osteogenic sarcoma. Cancer. 1956;9:1044–1052.
4. Zileli M, ÇAGL S, BASDEMIR G, ERSAHIN Y . Neurosurg Focus 15 (5):Article 5, 2003,1-6.
5. Poleksi Z. R., Lalosevic V. J., Milinkovi Z. B. Osteoblastoma of spine ACI Vol. LVII , 63-68.  

6. Samsadani A, Torre-Healy A, Chou D, Cahill AM, Storm P B. Treatment of osteoblastoma at C7: a multidisciplinary approach. A case report and review of literature. Eur Spine J ( 2009) 18 ( Suppl 2): S196-S200.
7. Mc Cleod RA , Dahlin DC, Beabout JW (1976) The spectrum of osteoblastoma . AJR Am J Roentgenol 126;321-325
8. Peivandi M T, Ameri E, Ganjavian S, Behtash H, Mobini B. Osteoblastoma of the spine. MJIRC, Vol.8, No.1, May 2005,52-56.
9. Boriani S, Capanna R, Donati D, Levine A, Picci P, Savini R. Osteoblastoma of the spine. Clin Orthop Relat Res. 1992 May;(278):37-45.
10. Javad M U, Scully S P. Enneking classification: Benign and manalignat tumors of the musculoskeletalsystem. Clin Orthop Relat Res (2010), 468: 2000-2002
11. Enneking WF, Spanier SS, Goodman MA. A system for the surgical staging of musculoskeletal sarcoma.1980. Clin Orthop Relat Res. 2003;415; 4-18
12. Berberoglu S, Oguz A, Aribal E, Ataoglu O. Osteoblastoma response to radiotherapy and chemotherapy. Med Pediatr Oncol. 1997 Apr;28(4):305-9.
13. Alessandro Gasbarrini , Stefano boriani, Case report: curetting OO of the spine using combined video-assisted thoracoscopic surgery and navigation . Clinical Orthopedics and related research, Feb 2013, vol 471, issue2, 680-685.
14. Kirwan E.O’G, Hutton P A N, Pozo J L, Ransford A O, Osteoid osteoma and benign osteoblastoma of the spine. Clinical presentation and treatment. The Journal of Bone and Joint Surgery, Vol.66-B, No.1, January 1984, 21-26.

Management of Pineal Region Tumors

The pineal gland develops during the second month of gestation as a diverticulum in the diencephalic roof of the third ventricle. It is flanked by the posterior and habenular commissures in the rostral portion of the midbrain directly below the splenium of the corpus callosum.  

Pineal tumors constitute 3-8% of pediatric brain tumor & 1% of brain tumors in adults.Germinoma is the most common tumor of Pineal tumor ( about 20 to 40%), followed by astrocytoma, teratoma and Pinealoblastoma.

Germ cell tumors, Ependymoma and Pineal cell tumors metastasize easily through the CSF ( “drop metastasis”).

Pineal region is situated at the posterior aspect of 3rd ventricle. Pineal stalk comprises of Posterior commissure and Habenular commissure. Many structures are situated in this region. Tectum of the mid brain and quadrigeminal plate ( superior and inferior colliculi) are situated beneath the Pineal gland. Splenium of the corpus callosum is situated above this gland. The CSF space around Pineal gland is known as Quadrigeminal Cistern.
Pineal region tumors are derived from cells located in and around the pineal gland. 

So, many types of lesions may be seen in the Pineal region:

1.Tumors arising from the Pineal Gland are tumors of neuroepithelial tissue & classified as Pineal Parenchymal Tumors (According to the revised WHO-2007 classification of CNS tumors: i. Pineocytoma, ii. Pineoblastoma, iii. Pineal parenchymal tumor of intermediate differentiation, iv. Papillary tumor of the Pineal region)
                   

                       Pineocytoma ( or Pinealcytoma) is well differentiated, arises from pineal                                                             epithelium.WHO Grade I, intense homogeous enhancement

                       Pinealoblastoma ( or Pinealblastoma) is malignant, WHO Grade IV,is a form of                                                   primitive neuroectodermal tumor (PNET), most often affects children, has                                             predilection for CSF dissemination, Lobulated, heterogenous enhancement
                        Both are radiosensitive 

2.Tumor from rests of germ cells: Germ Cell Tumors: Germinomas, Embryonal carcinoma, Endodermal sinustumor (Yolk sac tumor), Choriocarcinoma, Teratoma
                      Germinomas: Malignant
                      Non-germinomatous germ cell tumors (NGGCT); Embryonal carcinoma,                                                         choricarcinoma, & endodermal sinus tumor( also known as yolk sac carcinoma)                                    are usually malignat except Teratoma ( mature & immature)

3.Tumors from the glial cells ( Glial cyst or Pineal cyst, tectal Plate glioma which are usually pilocytic astrocytomas)

     Pineal Cyst
              Usually an incidental finding (ie,seen on about 4% of MRI of the patients who are not                                                                                       symptomatic due to lesion in the Pineal region)
              Commonly intra-pineal glial-lined cysts of less than 1 cm diameter.
              Etiology is not clear,  but considered as nonneoplastc and benign, and may be due to                                         ischemic glial degeneration or due to sequestration of the pineal diverticulum.
               It may contain clear or xanthrochromic or hemorrhagic fluid. Rarely it may enlarge &                                     become symptomatic as other Pineal masses. So, if size is less than 2cm, follow with                           annual imaging. If large & symptomatic: surgery( shunt, ETV,  cyst excision,                                       stereotactic or endoscopic aspiration)

4.Tumors from the Ependymal lining; Ependymoma

5. Tumors/lesions from arachnoid cells: Meningiomas, Arachnoid cysts

6. Tumors from sympathetic nerves: Chemodectomas

7. Tumors from remnant of ectoderm: Epidermoid, Dermoid

8. Tumors originating from elsewhere in the body: Metastasis (Absense of Blood Brain Barrier in the                                                                                                      Pineal land makes it susceptible site                                                                                                          for hematogenous metastasis)
9. Lesions which mimic tumors
                                      Vascular: Vein of galen aneurysm
                                      Infection: Neurocysticercus, Tuberculoma


Clinical Features of Pineal region masses
           Generally manifest in 3 ways: 
                           1. Symptoms of increased intracranial pressure from hydrocephalus 
                           2. Direct Brainstem and cerebellar compression
                           3. Endocrine dysfunction 


How to approach a case with a mass in Pineal Region? 

Take History:  History may give features of raised ICP like Headache, vomiting, or symptoms due to                         mass in the posterior third ventricular region: visual disturbances, lethargy, memory                             disturbances. 
Do Clinical examination : In infants: increased head circumference, seizures
                                          In boys with choriocarcinoma or germinomas with syncytiotrophoblastic                                                         cells: Precocious Puberty ( due to leuteinizing hormone-like effects                                                       of beta-hCG secreted in CSF
                                          Papilloedema
                                          Parinaud's syndrome (upward gaze palsy, converegence or retracction                                                                    nystagmus,light-near pupillary dissociation)
                                          Sylvian Aqueduct Syndrome (from further midbrain compression):                                                                      Paralysis of down-gaze or horizontal gaze, can be superimposed                                                            on Parinaud's syndrome
                                           Dorsal Midbrain Compression or infiltration can lead to lid retraction (                                                                Collier's sign) or ptosis. May appear as setting sun sign.
                                           Diplopia if 4th cranial nerve palsy.
                                           Ataxia
                                           Radiculopathy or myelopathy due to drop metastasis

Sometimes Blood & CSF investigations may give some clue to the diagnosis: 
       Germ cell tumor (GCT) may give rise to tumor markers in CSF
                   beta-human chorionic gonadotropin ( beta-hCG) is elevated in CSF in choriocarcinoma                                                and in about half of germinoma cases.
                   Alpha-fetoprotein (AFP) is elevated with endodermal sinus tumor, embryonal carcinoma                                              and immature teratoma.
                   Placental Alkaline Phosphatase (PLAP) is elevated in CSF & Serum of intracranial                                                      Germinomas. 
       CSF may be collected by ventricular tap if lesion is large or through Lumbar Puncture if lesion is                   small & if there is no risk of herniation, if a patient presents with hydrocephalus and                             patient is operated for CSF diversion procedure  like shunt or ETV then CSF should be                         collected and sent for tumor markers. 
                                   Although tumor markers alone are not usually sufficient for making a diagnosis                                    of a pineal tumorsince many of these tumors are mixed cell type.n But, when                                        positive, tumor marker can be followed serially to assess treatment and to                                              look for recurrence.
                  
Neuro-radiological evaluation : MRI of the brain with contrast with MR spectroscopy. It may                           diagnose neurocysticercus or tuberculoma.
              Some other investigations may be required if features are suggestive of systemic metastasis.
              MRI of cervical, dorsal & Lumbosacral spine to assess for drop metastasis.

Treatment:
Ideal situation is to know the histopathology of the lesion. o, ideal treatment is surgical excision followed by adjuvant therapy.But optimal management strategy is not to harm the patient. Pineal occupies a deep position near the geometric center. Since it is situated in the eloquent area of the brain and in close proximity to the splenium, superior colliculus and hypothalamus and close relation with the deep venous system including Vein of Galen, a judicious decision should be taken before operating the patient.
 
1. Observation & annual MRI if a lesion is asymptomatic as an incidental pineal cyst of less than 1              cm,
 
2. Radiosurgery: New modality of treatment , if tumor is less than 3 cm in size.
 
3. Surgery:
  Ventriculo-peritoneal shunt,
  Endoscopic Third Ventriculostomy (ETV),
  Endoscopic cyst excision,
  Computer Assisted Cisternal Endoscopic Approach (CACE): supracerebellar infratentorial approach
  Stereotactic or Endoscopic aspiration
  Craniotomy and Micro-neurosurgical excision of the mass:
               Midline infratentorial supracerebellar approach ( Horsley & Krause as refined by Stein)
                     Oppenheim & Krause in 1913 reported First successful removal of Pineal tumor.
                     Krause in 1926 reported 3 cases of infratentorial approaches without operative mortality
                           
               Occipital transtentorial approach ( Poppen's)
               Transcallosal approach : Dandy 1921
        The extensive variety of histologic subtypes found in the pineal region makes it imperative to             establish a tissue diagnosis. Aggressive Microneurosurgical resection followed by adjuvant                 therapy is mainstay of management.

4.Radiotherapy & Chemotherapy
 
If Biopsy is Germinoma: Radiotherapy and Chemotherapy
                    Germinomas are very sensitive to radiotherapy and chemotherapy. "Test dose" radiation                                 or "Trial XRT" of 5 Gy in a uniformly enhacing germinoma: if shrinks. Then XRT                               without surgery ( controversial as 36-50% of Pineal tumors are benign &                                                radioresitant}
 

Sources:

Mark S. Greenberg, Handbook of Neurosurgery, 7th ed., Thieme

emedicine.medscape.com/article/249945-overview ( Pineal Tumors, Author:Jeffrey N Bruce, MD; Chief Editor: Brian H Kopel)

Tandon PN, Ramamurthy R, Jain PKN. Ramamurthy & Tandon's Manual of Neurosurgery, Publisher: Jaypee

Jeffrey N.Bruce. Pineal Tumors. Chapter in Youmans Neurological Surgery, 6th ed. , H.Richard Winn, Elsevier Saunders,1359-1372.