Perspectives on Signet Ring Stromal Cell Tumor and Related Signet Ring Cell Lesions of the Gonads

In this article, we discuss advances in our knowledge of the pathology of signet ring stromal cell tumor and related signet ring cell lesions of the ovary and a single case of signet ring stromal cell tumor of the testis. We divide ovarian signet ring cell lesions into 3 categories that reflect differences in their pathogenesis and histologic appearance. With 1 exception, all authentic cases of signet ring stromal cell tumor have been unilateral. Cases of ovarian signet ring stromal cell tumor from the literature can arise in 2 ways. The majority of cases arise multifocally from fibroma, whereas the remainder likely arise directly from the ovarian stroma. In difficult cases, immunocytochemistry provides improved diagnostic accuracy in distinguishing signet ring stromal cell tumor and its mimics from Krukenberg tumor. The most useful antibodies in this regard are epithelial membrane antigen and vimentin.