Metastases from Colonic Adenocarcinoma

This is from a 40 y/o female who presented with abdominal pain and was found to have a left adnexal mass. She had undergone sigmoid colectomy four years previously for adenocarcinoma. The left ovary showed a 9 cm multinodular, cystic mass. The tumor was CK20+ and CK7-ve. The findings were consistent with metastatic colorectal adenocarcinoma. Note the involvement of surface by the tumor. Primary ovarian tumors tend to have a smooth external surface. Metastatic colorectal adenocarcinomas can simulate mucinous, endometrioid, clear cell, and secretory subtype of primary ovarian carcinomas.