ONCOCYTIC CYSTADENOMA OF THE PAROTID-GLAND WITH PROMINENT SIGNET-RINGCELL FEATURES

A case of distinctive benign cystadenoma of the parotid gland composed of several different morphological components is presented. The most conspicuous morphological component and the largest part of the neopla sm was represented by solid sheets of oncocytic cells surrounded by my oepithelial cell layer. Most oncocytic cells possessed large intracyto plasmic vacuoles with the nuclei displaced towards the periphery, impa rting them with a striking signet-ring cell appearance. The size of th e intracytoplasmic vacuoles ranged from 4 to 50 mu m. Immunohistochemi cally these signet-ring cells lacked immunoreactivity for S-100 protei n and cytokeratin but they strongly stained for antimitochondrial anti body 113-1. The present case illustrates an unusual, hitherto undescri bed, morphological feature of benign oncocytic cystadenoma of the paro tid gland.