Ovarian metastasis of colorectal adenocarcinomas. A clinico-pathological study of 41 cases

We report a series of 41 ovarian metastases from colorectal adenocarcinomas. The patients'mean age was 57.1 years at the time the metastasis was discovered, and 55.8 years at the time the primary carcinoma was found. The diagnosis of the primary tumour was anterior to the metastasis in 25 cases (mean interval 21 months), simultaneous in 13 and posterior in 3 others. The metastases formed cystic and solid masses with a mean weight of 330 g. The endometrioid architectural type was the most frequent, either pure (71%, 29/41) or associated with a mucinous component (17%, 7/41). Pure mucinous or other architectural types were rare. The endometrioid type was characterized by glands with a garland pattern, and intraluminal dirty tumoral necrosis. Immunohistochemistry helped to distinguish the metastases of endometrioid type from serous or endometrioid primary ovarian carcinoma; 71% of the former were CK7(-)/CK20(+), and 100% of the latter had the reverse profile CK7(+)/CK20(-).