**5.2 Immunophenotypic features of ovarian mucinous carcinomas**

Immunohistochemistry of OMCs is characterised by diffuse intense positivity for CK7 and variable positivity for CA19-9, CEA, CK20 and CDX2 focal weak positivity for PAX8 can be seen in a subset of tumours [111, 112], whereas WT1, Napsin A, Vimentin, CA125, ER and PgR are mostly negative. SATB2 is rarely expressed in ovarian mucinous tumours (5–7%) and its expression is associated with the presence of mature teratoma [113] p53 may demonstrate wild-type or mutation-type immunoreactivity and p16 is usually negative or focally positive [114, 115].
