cavernous hemangioma is a benign vascular malformation and belongs to a wide and continuous overlapping spectrum of hamartomas .
most cavernous haemangiomas occur in the vertebral body and may extend into the epidural space .
purely extradural cavernous hemangiomas without any vertebral body involvement is extremely rare and accounts for only 4% of all extradural spinal tumors and 12% of haemangiomas occurring extradurally .
we herein present a rare case of extradural dumbbell lumbar ( l3 ) cavernous hemangioma with paraspinal extension .
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 .
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 .
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 .
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 [ figure 1 ] .
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 .
shows irregularly shaped well defined extradural lesion ( arrows ) , hypointense on t1w ( a ) , hyperintense on t2w ( b ) images with homogenous contrast enhancement ( c , d , e ) and paraspinal transforaminal extension ( d , e ) the 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 .
left l3 nerve root was pushed superiorly by the tumor and it was not arising from any neural tissue .
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 .
microscopic 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 [ figure 2 ] .
radiotherapy was administered to the residual paraspinal portion of tumor [ figure 3 ] . for radiotherapy ,
the patient was immobilised in a vacuum locking device and ct simulation was done in the treatment position .
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 .
three dimensional conformal radiotherapy was planned on eclipse 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 .
( a , b ) the proliferating and anatomizing capillary channels lined by endothelial cells ( h and e , 100 ) shows postoperative changes ( arrow ) in spinal canal and residual tumor in paraspinal region
cavernous hemangioma is a benign vascular malformation , also known as cavernous malformation , cavernous angioma or cavernoma .
the cavernous hemangiomas occur throughout the neuroaxis including both intracranial and spinal compartments . according to location ,
its incidence in supratentorial , infratentorial and spinal compartments is 80% , 15% and 5% respectively .
purely extradural spinal cavernous hemangiomas are rare and the extension through intervertebral foramen into extraspinal region ( dumbbell ) is still rarer . in that case , it can be confused with commonly diagnosed nerve sheath tumors .
the onset of symptoms in these spinal cavernomas may be acute , progressive or remittent , depending on the biological behavior of the tumor .
lumbar extradural hemangiomas behave differently , not only from intramedullary cavernous hemangiomas but also from extradural cavernomas of other spinal locations .
purely extradural hemangiomas should be included in the differential diagnosis of lumbar extradural soft - tissue lesions .
in contrast to intracerebral cavernous hemangiomas , the patterns of density on ct scans and signal intensity on mr images are more homogenous in extradural hemangiomas .
another point of differentiation is the absence of low signal rim ( hemosiderin ) which is usually seen in intraaxial spinal cord cavernomas . as seen in present case , extradural cavernous hemangiomas
are usually isointense on t1w and hyperintense on t2w images and show homogenous contrast enhancement because of the presence of sinusoidal channels .
the lesion should be differentiated from other epidural neoplastic or inflammatory conditions , such as meningioma , neurofibroma , lymphoma , hemorrhagic vascular mass , granuloma and angiolipoma .
complete and in toto excision of the lesion should be attempted for clinical improvement ; however , in case of subtotal excision , adjuvant radiotherapy is advised .
radiosurgery as primary or adjuvant therapy is increasingly becoming an option as advances in radiosurgical equipment are enabling safe and accurate targeting of lesions .
though purely extradural cavernomas are rare in occurrence , they should be considered as possible differential diagnosis of dumbbell lesions of spine in view of operative nuances ( especially massive haemorrhage ) and management thereof .
 a 52-year - old female presented with slowly progressive left lower limb polyradiculopathy . 
 mri of the lumbar region revealed an extradural dumbbell mass at l3 vertebral level , isointense on t1w and hyperintense on t2w images with homogenous contrast enhancement and extending into paraspinal region through left l3/4 foramen . 
 l2 to l 4 left hemilaminectomy and excision of intraspinal part of tumor was performed . 
 histopathological examination revealed presence of cavernous hemangioma . 
 this case is reported because of its rarity , unusual dumbbell shape of lesion and difficulty in making a preoperative diagnosis without a coexisting bone lesion . 