Neurology India, Vol. 58, No. 2, March-April, 2010, pp. 329-330
Letter To Editor
Hemorrhage in acoustic neurinoma
Batuk Diyora, Alok Sharma, Prerna Badhe, Naren Nayak
Department of Neurosurgery, L.T.M.G. Hospital, India
Correspondence Address: Batuk Diyora, Department of Neurosurgery, L.T.M.G. Hospital, India, firstname.lastname@example.org
Date of Acceptance: 08-Oct-2009
Code Number: ni10088
Hemorrhage in acoustic neurinoma is very rare and only few cases are reported in world literature.  Large size, mixed Antoni type and secondary vascular changes are thought to be risk factors. Gradual onset of unilateral hearing loss and tinnitus are the usual initial symptoms. Unusually, presentation can be of catastrophic onset resulting from sudden, massive intratumoral hemorrhage or subarachnoid hemorrhage.
A 55-year right-handed male was brought to our hospital with severe headache, vertigo and vomiting while voiding in early morning hours. He had complete lower motor neuron type facial palsy on the right side. Rinne′s test was positive and Weber′s was lateralizing to the left side. Gag reflex was absent on right side. Power in all four limbs was normal along with normal reflexes except extensor planters on both the sides. Computed tomography (CT) scan of the brain showed bleed in right cerebello-pontine (CP) angle region [Figure - 1]a. Magnetic resonance imaging (MRI) revealed a tumor in right CP angle with blood clot within it [Figure - 1]b. Right suboccipital craniectomy was performed and complete excision of the tumor ensured. Histopathological examination of the specimen showed mixed patterns of Antoni type A and B cells with area of increased vascularity [Figure - 2]. Lower cranial nerve function completely improved over a period of 4-6 weeks but very little improvement in facial function was observed at four-year follow-up.
About 1.4 to 10% of patients of brain tumor present with sudden hemorrhage; hemorrhage in to acoustic neurinoma is very rare. Besides metastatic and malignant glial tumors, melanoma, primary pituitary adenocarcinoma and choroids plexus papilloma may present with intratumoral bleed. Occlusion of the intratumoral vessels, distal vessels necrosis because of vascular endothelial proliferation and erosion of the vessels wall by the tumor are the possible mechanisms of intratumoral bleed. Marked increase in arterial and venous pressure by physical exercise and traumatic contusion of tumor may rupture fragile tumor vessels resulting in massive haemorrhage in acoustic neurinoma. We also agree partially with the above hypothesis as in our case an act of micturition might have raised intraabdominal pressure as well as intracranial venous hypertension, which might have led to sudden bleeding in a previously existing CP angle tumor having fragile tumor vessels. Hypertension, contusion of the tumor, rapid growth are also blamed for hemorrhage in acoustic neurinoma. ,, A rapidly growing tumor disrupts adjacent thin-walled and dilated vessels leading to massive hemorrhage into the surrounding tissue, where stromal support is weak. Rate of acoustic neurinoma growth is variable, estimated in most cases at 2 mm/year. MIB -1 staining index (SI) shows a good correlation with tumor doubling time of acoustic neurinoma. Ohata described a case report of massive hemorrhage in acoustic neurinoma with high MIB-1 staining index of 2.86%.  In our case, the MIB staining index was 0.6%. We think that hemorrhage may not be always associated with the rapid growth of the tumor.
Prognosis of patients with intracranial hemorrhage secondary to neoplasm is usually poor. However, the prognosis was not bad in a review of the 38 reported cases. ,, As surgical evacuation of hematoma and tumour excision is the preferred method of treatment for hemorrhage in acoustic neurinoma. Of the 36 patients underwent surgery, only two patients died and the rest all had uneventful postoperative course and good outcome with or without cranial nerve deficit.  .
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