1. Case Report

33 years old female, no chronic medical condition, presented to emergency department with the complaints of low back pain radiating to right lower limb for the past 3months with exacerbation of symptoms since 2 weeks, necessitating repeated visits to ED. She also complained of urinary retention and weak urine stream for one day prior to presentation.

1.1 Examination on admission

Patient seemed to be in distress because of pain.Power  in both limbs was grossly 4+/5, numbness both LL, saddle anesthesia, lax anal tone. Deep tendon reflexes seemed to be normal. An urgent MRI revealed anIntradural mass at L3-L4 vertebral level with intense enhancementlabelled by radiologist as meningioma.

1.2 Operation

The tumor was exposed byL3 total and L4 partial Laminectomy.The tumor waswell circumscribed, highly

Vascular. Multiple blood vessel were covering the tumor.

Complete excision of intradural extramedullary lesion was achieved by microdissection.The patients recovery was uncomplicated. Post operatively she received active Physio and rehabilitation.Patient did not have any neuro deficit at discharge.

1.3 Follow up

Followed in OPD at 4 months. No neurological deficits. Screening MRI of brain and whole spine showed no evidence of any associated lesion. Other screening for VHL came out to be negative.

PRE-OP MRI :

POST-OP MRI:

1.4 Pathology slides

1.4.1 Pathological examination: Sections show a well-circumscribed lobular proliferation of closely packed variable sized capillaries (Figure 1). The capillaries are lined by bland endothelium. The interstitium between the capillaries show stromal cell proliferation with vacuolated cytoplasm and occasional hyperchromatic nuclei (Figure 2). By immunohistochemistry, the interstitial cells are focally positive with CD68 while negative with CD31, CD34, Inhibin, EMA, GFAP and S-100. The rich capillary network ishighlighted with CD34 andCD31 (Figure 3).

2. Discussion

Hemangioblastoma are benign neoplasm of the CNS and they are basically classified as meningeal lesions of uncertain origin [1, 2]. Hemangioblastomas are rare, accounting for 1-5% of all spinal cord tumours.^K1 75% of the Spinal hemangioblastoma are Intramedullary, and another 10-15% have combined intramedullary and extramedullary-intradural component, while isolated Extramedullary hemangioblastoma are rare^K1 and associated with Pia mater. They most frequently are localized at the level of the cervical and thoracic vertebrae [3]. On the axial plane, the epicenters of hemangioblastomas are most commonly found in the posterior aspect of the spinal cord, in the region of the dorsal root entry zone [3, 4]. Chang  Hyun Park [5], in a single center study from 2003-2012, have operated on 16 cases of Spinal Hemangioblastoma out of which 12 were solitary sporadic  and 4 fulfilled the criteria of VHL, and all of these were intra-medullary. Out of the 12 solitary, 7 were cervical, 4 were thoracic and one at L1/2 level. The 4 patients with  VHL had multiple and all were in cervical or thoraxic region with one intramedullary at L1. This study  again shows the occurrence of solitary extramedullary Lesion is a rare entity [5]. Von Hippel-Lindau syndrome is autosomal dominant disorder with incomplete penetrance that has variable manifestations, linked to loss of function and mutation in the tumor suppressor gene on Chromosome no 3. Intramedullary Hemangioblastoma are seen in 10-30 % of patients with VHL syndrome. VHL syndrome is usually  manifesting itself as central nervous system hemangioblastomas, renal cysts, and renal cell carcinomas. Other lesions include retinal angiomas, pheochromocytomas, pancreatic cysts, and epididymal cystadenomas. Tumours that are rich in   blood vessels grow in the neural tissue in these tumours are called hemangioblastomas. cerebellum, cervical spine is the most common location of these tumours .spinal hemangioblastoma patients tend to present with neurological symptoms And signs at a younger age, and experience multiple small lesions .these tumours are only diagnosed when they are associated with compression effect and loss of function due to mass effect on the surrounding nervous tissue. Radical advancement of hemangioblastomas from solid to cystic component. Patients usually appear with symptoms due to mass effect, most often from an enlarging peritumoral cyst. An awareness of this advancement can assist in clinical decisions concerning follow-up intervals and the timing of surgical intervention. Our review of literature shows that a haemangioblastoma is actually rare entity and it does not occur commonly in the spinal cord. According to the literature the most common location is the posterior cranial fossa [6] and the second most common location comes out to be the spinal cord  followed by spinal nerves, brain stem, thalamus and pituitary stalk [7, 8]. Infact spinal cord lesions account for very small percentage of the primary tumors overall, furthermore most of the patients that come with this lesion  have actually and underline pretext to it that is VHL syndrome [9]. The actual incidence of sporadic lesion is unknown, one study [10] showed 20% of the cases have sporadic lesions and in our case we also think that this is a sporadic and  isolated lesion  as the patient does not have any other manifestations of Von Hippel Lindau syndrome, clinically or radiologically. Literature shows that sporadic lesions present much later in life and have less neurological symptoms as compared to the other counterpart with VHL syndromepatients. Also these patients  are at  much higher risk of recurrence, These patients usually require a lifelong surveillance and serial imaging to rule out other lesions [11]. In patients with sporadic and isolated lesions of hemangioblastoma, only 4% of the patients have detectable mutations in the respective VHL gene, however, new literature shows that these mutations are only specific to hemangioblastoma and have lower penetrance [12]. Because of the slow growing nature of the tumor mostly patients are asymptomatic, gets symptomatic because of local compression of neurological tissue from the mass lesion, mostly associated with the Back Pain, which later on may involve sensory loss or motor loss. VHL syndrome is a genetic disorder that is autosomal dominant in nature, and it is caused  by mutations of the VHL tumour suppressor gene which is a germline mutation present on  little arm of the third chromosome (3p25-26). The prevalence is  1:40000 to 1:50000. VHL syndrome is usually  manifesting itself as central nervous system hemangioblastomas, renal cysts, and renal cell carcinomas. Other lesions include retinal angiomas, pheochromocytomas, pancreatic cysts, and epididymal cystadenomas. Tumours that are rich in   blood vessels grow in the neural tissue in these tumours are called hemangioblastomas. cerebellum, cervical spine is the most common location of these tumours .spinal hemangioblastoma patients tend to present with neurological symptoms And signs at a younger age, and experience multiple small lesions .these tumours are only diagnosed when they are associated with compression effect and loss of function due to mass effect on the surrounding nervous tissue. Radical advancement of hemangioblastomas from solid to cystic component. Patients usually appear with symptoms due to mass effect, most often from an enlarging peritumoral cyst. An awareness of this advancement can assist in clinical decisions concerning follow-up intervals and the timing of surgical intervention. Tumour resection is the mainstay of management and  can be curative for patients with solitary lesions, but constant follow-up is essential due to the high frequency of mutations in these  patients with these tumours and a possible risk of a new tumour. Most of the literature we encountered patients had follow up for 1 to 2 years continuously. In a study done by  Sven and Frank  [14], and literature review  follow-up after treatment for sporadic CNS hemangioblastoma were not found in the current literature. Based upon their experience they  suggested to  perform a MRI scan of the involved neuronal axis at 6 and at 12-24 months in the postoperative period. These follow-up modalities are to be advanced or extended based upon clinical indication. After intervention for a VHL associated lesion, there are detailed follow-up schedules available. The literature suggests performing a yearly MRI driven craniospinal control as well as an annual ophthalmoscopy, a yearly abdominal ultrasound with triennial computed tomography (CT) imaging, a yearly audiometry and pheochromocytoma investigation by urine analysis (metanephrine – VMA) Based upon clinical indication these follow-up modalities should be advanced or extended.

3. Conclusion

Tumour resection is the mainstay of management and  can be curative for patients with solitary lesions, but constant follow-up is essential due to the high frequency of mutations in these  patients with these tumours and a possible risk of a new tumour. Most of the literature we encountered patients had follow up for 1 to 2 years continuously. Once considered a rare entity the actual incidence rate of isolated intradural extramedullary Hemangioblastoma still remains unknown Keeping a higher index of suspicion in mind, a thorough review of MRI can lead to higher index of diagnosis pre-operatively. Total tumor resection appears to be one of the best options of treatment.

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