Primary ovarian signet ring cell mucinous carcinoma:is a real entity or is a missing primary neoplasm in another organ?

implants, presence of tumor cells within mucin, solitary cell invasion of stroma, extraovarian dissemination, and extensive lymphovascular invasion, particularly at the ovarian hilum, are indicative of a secondary mucinous neoplasm. 6To differentiate between primary and metastatic signet ring cell mucinous carcinoma of the ovary, immunohistochemistry may be applied as an additional method.However, the distinction between primary and secondary ovarian mucinous neoplasms remains challenging due to the fact that many primary tumors demonstrate intestinal differentiation and express enteric markers such as CK20, CA 19-9, ACE, CDX2, and CK7. 7,8