Endolymphatic sac tumor: A case report and review of the literature

BACKGROUND Papillary tumors of the temporal bone are very rare but aggressive neoplasms. In the past, a middle-ear origin was presumed. Only recently convincing evidence exists that these tumors in fact arise from the endolymphatic sac. METHODS We present a case of an endolymphatic sac tumor (ELST) with detailed clinical, imaging, operative, and pathologic data. The literature on this rare tumor type is reviewed. RESULTS This 63-year-old woman had a progressive mass lesion in the temporal bone for a period of more than 35 years, resulting in unilateral fifth to eleventh cranial nerve palsy, progressive ataxia, and a pyramidal and pseudobulbar syndrome. Computerized tomography (CT) and magnetic resonance imaging (MRI) showed a tumor invading the pars squamosa and petrosa of the temporal bone, and extending into the middle and posterior fossa. Angiography demonstrated a hypervascular tumor mass. The patient underwent surgery, with nonradical removal of a tumor. Histologic examination demonstrated a papillary ELST. A search through the literature revealed 36 patients with ELST, based on convincing anatomic and histologic considerations. CONCLUSIONS It is important to make a distinction between ELST and the more benign middle-ear adenomas, since this leads to a different treatment and prognosis. ELST frequently invades the surrounding structures and extends intracranially. The treatment of choice is a radical resection, although complete resection is impossible in most of the cases. The value of adjunctive radiation therapy remains controversial. (C) 1997 by Elsevier Science Inc.