MIXED TUMOR OF SCHWANNOMA AND MENINGIOMA COMPONENTS IN A PATIENT WITHNF-2

The authors present the case of an intracranial tumour consisting of b oth schwannoma and meningioma within the same tumour, in a patient wit h neurofibromatosis-2 (NF-2). A pre-operative diagnosis of this mixed tumour was not made. However, retrospectively, a meningiomatous area w as found inside the acoustic neurinoma on magnetic resonance (MR) imag es. Predominant schwannoma with a minor component of meningioma was co nfirmed by histopathological and immunohistochemical examinations. The transitional zones of these two different rumours were macroscopicall y sharp but microscopically interdigitated. The patient had another me ningioma and schwannoma in a separate section of the cranial cavity. B ased on this patient, it is suggested that the collision of two kinds of tumours is the most likely hypothesis to explain the development of mixed components of schwannoma and meningioma within the same tumour.