Ovary, metastatic mucinous neoplasm

Mucinous tumours of the ovary are relatively uncommon, accounting for about 25% of all ovarian tumours. They can be large and cystic, and are characterized by a lining of tall columnar epithelial cells with apical mucin. In many cases, mucinous tumours of the appendix can metastasize to the ovary, and discerning the primary site can be difficult. Immunohistochemistry in this case is positive for CK20 and negative for CK7 (see supplemental images in the Related Content section), and subsequently, a mucinous tumour of the appendix was identified. (This is image 1 of 2 from the same case; see linked image in the Related Content section.)