Lumbar extradural dumbbell cavernous hemangioma: A rare lesion
A 52-year-old female presented with insidious onset progressive low backache with pain radiating to whole of left lower limb associated with paraesthesias for two months. She had difficulty in walking due to pain. There were no symptoms suggestive of bladder or bowel involvement. General examination was unremarkable. Upper limbs were normal with no sensorimotor deficits. Left lower limb power was 4/5 in hip flexion, extension, abduction and adduction, 4/5 in knee flexion and extension, subtle weakness in ankle flexion and extension and great toe extension with hypotonia. Right side lower limb power was normal. The reflexes of left lower limb were sluggish whereas on right side they were brisk (normal). Sensory examination revealed impairment of all the modalities of sensations (pin prick, touch, temperature, vibration- impaired upto anterior superior iliac spine) from L2 to S4 dermatomes on left side. There was no spinal tenderness or deformity. Rest of examination was unremarkable. Magnetic resonance imaging of lumbar spine revealed an irregularly shaped, well defined extradural lesion at L3 vertebral level indenting the body, displacing the thecal sac posterolaterally and extending into left paraspinal region through L3- 4 neural foramen. Lesion was isointense on T1W, hyperintense on T2W images with strong homogenous enhancement on Gadolinium contrast study []. Provisional preoperative diagnosis of schwannoma was considered. Though the clinical findings and radiology were not concordant, the patient was suggested surgical intervention for the presence of enhancing mass lesion noted on the imaging with guarded prognosis.\nThe patient underwent left hemilaminectomy from L2 to L4. There was an extradural, brownish red, highly vascular mass located anterolateral to thecal sac at L3 vertebral body with well defined capsule around it. It was extending into left paraspinal region through L3/4 neural foramen. Left L3 nerve root was pushed superiorly by the tumor and it was not arising from any neural tissue. It was highly vascular and bleeding heavily on taking a small biopsy. The capsule was then coagulated to control the haemorrhage. It was dissected clear from the L3 nerve and the dura keeping the dissection over the coagulated capsule. The spinal component of the lesion was excised in toto until the neural foramen, where it was coagulated and was cut sharply leaving behind the extra-foraminal portion. Perfect haemostasis was achieved using bipolar cauterisation, cross checked by Valsalva manoeuvre. Scalloping of L3 vertebral body was noted following tumor excision.\nMicroscopic examination revealed numerous dilated vascular channels of variable sizes lined by a single layer of flattened epithelial cells and filled with blood elements. Interspersed thick hyalinised blood vessels and mature adipose tissues were noted []. The histological picture was characteristic of cavernous hemangioma. Radiotherapy was administered to the residual paraspinal portion of tumor []. For radiotherapy, the patient was immobilised in a vacuum locking device and CT simulation was done in the treatment position. CT images were fused with the preoperative and post operative MR images. Margin of 1 cm was added to the post contrast T1W MRI to obtain the clinical target volume; planning target volume was obtained by adding a margin of 0.5 cm to the clinical target volume. Dose was prescribed to the planning target volume. Three dimensional conformal radiotherapy was planned on ECLIPSETM planning system (Varian Medical systems, Palo alto, CA) on linear accelerator (Clinac iX- 3665) using 6 MV X rays. The dose prescription was 40 Gy, 2 Gy per fraction, 20 fractions given five days a week over five weeks.