Primary ovarian carcinoma versus metastatic colorectal carcinoma: immunohistochemical and electron microscopic studies

ABSTRACT

Ovarian metastasis from colorectal carcinoma frequently mimics primary ovarian carcinomas. The present study was performed to find possible histopathological criteria helpful in the differential diagnosis. Twelve cases of primary colonic adenocarcinoma with unilateral [5/12] or bilateral [7/12] ovarian metastasis as well as 12 cases of primary ovarian carcinoma of unilateral [7/12] and bilateral [5/12] were included in this study. Both were evaluated clinicopathologically, ultrastructurally and immunohistochemically including CK-7 and CK-20. The integration of the clinicopathological and immunohistochemical findings was very helpful, while electron microscopy had less value in the determination of primary ovarian carcinoma from ovarian metastasis of colonic origin. Bilaterally, extrapelvic spread, high mitotic index, garland, segmental and dirty necrosis, positivity for CK-20 and lack of CK-7 immunoreactivity favored the diagnosis of ovarian metastases from colon carcinoma