The mechanisms of hemorrhage from an acoustic neurinoma are not clarified yet. Tumors larger than 2 cm in diameter, with mixed Antoni types and dilated thin-walled vessels,7,8 combined with a ruptured aneurysm,2 or rapid growth,10 are apt to hemorrhage. In our case, no gross hemorrhage was visible; hemosiderin was presented in both macrophages and in tumoral tissues under a microscope. Cystic formations were also found, which probably resulted from intratumoral bleeding. Histological examination showed a mixture of Antoni types A and B. There were several hypervascular areas characterized by numerous dilated thin-walled vessels in the tumor. The tumoral vessels are often composed of endothelial wall, showing intense proliferative areas through which hemorrhage occur easily.
Early surgical intervention is feasible for acoustic tumors in patients with NF2, with high rates of hearing and facial nerve function preservation.11 We removed the two tumors totally through bilateral suboccipital craniotomies. During a 3-year follow-up, the patient has “serviceable” hearing and normal facial nerve function.
1. Yonemitsu T, Niizuma H, Kodama N, Fujiwara S, Suzuki J. Acoustic neurinoma presenting as subarachnoid hemorrhage
. Surg Neurol 1983; 20: 125-130.
2. Kodama T, Matsukado Y, Takamoto K. Acoustic schwannoma presenting as subarachnoid hemorrhage
due to ruptured contact aneurysm. Surg Neurol 1987; 27: 77-80.
3. McCoyd K, Barron KD, Cassidy RJ. Acoustic neurinoma presenting as subarachnoid hemorrhage
. Case report. J Neurosurg 1974; 41: 391-393.
4. Gleeson RK, Butzer JF, Grin OD Jr. Acoustic neurinoma presenting as subarachnoid hemorrhage
. Case report. J Neurosurg 1978; 49: 602-604.
5. Shepard RH, Cheeks RE. Subarachnoid hemorrhage
and acoustic neurinoma. J Neurol Neurosurg Psychiatry 1981; 44: 1057.
6. Castillo R, Watts C, Pulliam M. Sudden hemorrhage in an acoustic neurinoma. Case report. J Neurosurg 1982; 56: 417-419.
7. Arienta C, Caroli M, Crotti FM. Subarachnoid hemorrhage
due to acoustic neurinoma. Case report and review of the literature. Neurochirurgia (Stuttg) 1988; 31: 162-165.
8. Misra BK, Rout D, Bhiladvala DB, Radhakrishnan V. Spontaneous haemorrhage in acoustic neurinomas. Br J Neurosurg 1995; 9: 219-221.
9. Inoue T, Miyamoto K, Kushima Y, Kodama H, Nishibori H, Hosoe H, et al. Spinal subarachnoid hematoma compressing the conus medullaris and associated with neurofibromatosis type 2. Spinal Cord 2003; 41: 649-652
10. Ohta S, Yokoyama T, Nishizawa S. Massive hemorrhage into acoustic neurinoma related to rapid growth of the tumour. Br J Neurosurg 1998; 12: 455- 457.
11. Brackmann DE, Fayad JN, Slattery WH 3rd, Friedman RA, Day JD, Hitselberger WE et al. Early proactive management of vestibular schwannomas in neurofibromatosis type 2. Neurosurgery 2001; 49: 274-280.