Gastric signet-ring cell carcinoma metastasis to bilateral ovarian granulosa cell tumors.

Tumor-to-tumor metastasis is a rare phenomenon. On the basis of our review of international literature, there have been 7 reports of tumor-to-tumor metastasis cases involving ovary neoplasms as the recipient. However, an ovarian granulosa cell tumor has not been reported to be a recipient. Here, we report the first case of gastric signet-ring cell carcinoma metastasis to a bilateral ovarian granulosa cell tumor. Awareness of this phenomenon is important to avoid incorrect diagnoses when encountering unusual morphologic features in ovarian granulosa cell tumors.