Clinicopathological Characteristics of Ovarian Metastasis from Colorectal and Pancreatobiliary Carcinomas Mimicking Primary Ovarian Mucinous Tumor

Background/Aim: A subset of carcinomas metastatic to the ovary can exhibit growth patterns closely resembling ovarian mucinous cystadenoma and borderline tumor. They can be misinterpreted as underlying primary ovarian mucinous tumors and can be erroneously used to suggest that the carcinomatous component arises from mucinous precursor lesions. Materials and Methods: We investigated the clinicopathological characteristics of 11 cases of metastatic carcinoma that had metastasized from colorectal and pancreatobiliary carcinoma and mimicked primary ovarian mucinous tumors. Results: The patient age ranged from 37 to 81 years old. Seven patients presented to gynecologists with nonspecific pelvic symptoms similar to those of primary ovarian tumors. The primary tumor was identified before the detection of the ovarian lesion in 6 cases, synchronously in 5, and postoperatively in 1 case. The ovarian tumors were bilateral in 6 cases. The greatest dimension of the metastatic tumors ranged from 4.8 to 23.0 cm. Multinodularity was present in 7 cases, and surface involvement was identified in 5 cases. An infiltrative growth pattern was present, at least focally, in 8 cases. Six and 2 cases exhibited cystadenomatous and borderline-like growth patterns, respectively. Conclusion: Although the diagnosis of metastatic tumors to the ovary is possible in most cases on the basis of clinical presentation and standard diagnostic criteria, their differential diagnosis may be problematic because of morphological patterns that strikingly overlap with those of primary ovarian benign, borderline, and malignant mucinous tumors. The possibility of metastases should be considered when evaluating ovarian mucinous tumors.