Cytological features of endolymphatic sac tumors: Case studies with review of literature.

Endolymphatic sac tumors are extremely rare, locally aggressive neoplasms that arise from the endolymphatic sac or duct, primarily in the intraosseous portion. These neoplasms show diverse histomorphological architectures and despite a bland cytologic appearance, can locally recur. Although the clinicopathological and radiological features of this entity are well characterized, the literature on cytological features is extremely sparse. Herein, we describe the cytological features of the endolymphatic sac tumors and discuss the relevant differential diagnoses.