Type of Preparation: ThinPrep/ LBP Magnification: Medium Clinical History: 66 year old postmenopausal woman presents with a pelvic mass and ascites Interpretation: Adenocarcinoma, extrauterine Cytomorphologic Criteria: Papillary three-dimensional clusters of cells with enlarged nuclei and very scant cytoplasm. Note nuclear molding and overlap. Explanatory Notes: In liquid-based preparations, the three-dimensional nature of the papillary clusters may make evaluation of the component cells difficult. Follow-up: Biopsy proven papillary adenocarcinoma in omentum and peritoneal implants - presumed ovarian primary