Cytologic Distinctive Features of Brenner Tumor

Herein, we present two cases of Brenner tumor, a rarely occurring neoplasm in the ovaries, obtained via intraoperative fine needle aspiration. The borderline Brenner tumor exhibited marked squamous metaplasia, characterized by individually distributed atypical squamous cells. A benign Brenner tumor associated with mucinous cystadenoma evidenced typical mucinous metaplastic features and transitional foci. These distinctive features may prove helpful in differential diagnosis of varied ovarian tumors, and particularly for intraoperative consultation.