Contributed by Deepali Jain, MD, DNB1, Sunita Bhalla, MD, Veer Singh Mehta2, MS, Mch
1Department of Pathology, Sir Ganga Ram Hospital, New Delhi, India
2Department of Neurosurgery, Paras Hospitals, Gurgaon, Haryana, India
A 48- year- old female presented with right sided moderate to severe headache for 2 years. She also had difficulty in right lateral vision for 4-5 months. For the last 2 months she developed difficulty in swallowing liquids and solids. The patient was unable to walk properly and had a tendency to fall on her right side for last 15 days. Her past history was significant for hypertension for which she was taking antihypertensives. On neurological examination, the patient was conscious and oriented. There was right sided cranial nerve palsy which includes III, IV, V, IX, X and XI nerves. The cerebellar signs were positive on right side. The MRI showed a mass lesion probably in relation to trigeminal nerve on right side showing extension anteriorly to Meckels cave and posteriorly to the cerebellopontine angle. The lesion was hyperintense on T2 and hypointense on T1 weighted images. After the administration of intravenous contrast gadolinium DTPA, the lesion showed moderate to intense homogenous enhancement. The lesion extended into the cavernous sinus and petrous bone on the right side. It measured 5.7x3.1x5.5 cm. The lesion was causing marked indentation of the pons and pontocerebellar junction on the right side. The rest of the brain parenchyma revealed no abnormal signal intensity. These findings were suggestive of a right trigeminal nerve schwannoma showing extension and mass effect or a petrous meningioma. Patient underwent suboccipital retrosigmoid craniotomy with excision of the mass lesion.
Histopathology showed a tumor which is primarily composed of lobules of paucicellular stroma (Fig. 1). In a few places the stroma is abundant (Fig. 2). Rare biunucleation is evident; however no mitosis is seen (Fig. 3). No physaliphorous cells were found. The tumor cells are positive for S-100 immunostains (Fig. 4). Cytokeratin stain was negative. Ki-67 labeling index was much less than 1% in tumor cells.
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