Objective: To study the distinctive clinicopathologic and immunohistochemical difference between ovarian metastatic carcinomas and primary ovarian carcinomas.
Methods: The clinical and pathological features of 27 cases of ovarian metastatic carcinomas (gastric carcinomas 12 cases, colon carcinomas 11 cases, others 4 cases) obtained from our department were reviewed. Immunostainings for CK (AE1/AE3), CK7, CK20, CEA, vimentin, nm23 were performed with SP staining methods.
Results: On gross examination, metastasis from gastric adenocarcinoma were usually bilateral, while solid (11/12) and metastases from colonic adenocarcinoma were more often unilateral and cystic (7/11). Microscopically, metastases from gastric adenocarcinoma revealed signet ring cells or poorly differentiated adenocarcinomas (12/12), whereas metastases from colonic adenocarcinomas showed similar morphology of endometrioid adenocarcinoma (8/11). The majority of ovarian metastases of gastric carcinoma (7/12) and colon carcinoma (8/11) were CK20 positive. In particular, CK20 was invariably expressed in colon cancer metastases. Most of the ovarian metastatic carcinomas from the gastrointestinal tract failed to react with immunostaining of CK7. A combined use of CEA, vimentin and nm23 had made a correct classification for 11/12 cases of the gastric carcinoma, 10/11 cases of the colonic cancer.
Conclusions: CK7 and CK20 have been proved to be useful antibodies in distinguishing between metastatic carcinomas and primary carcinomas of the ovary. Combined use of a panel of antibodies can give more significant results.