[Clinicopathologic study of seromucinous carcinoma of ovary]

Objective: To elucidate the clinicopathologic characteristics, immunophenotype and differential diagnosis of ovarian seromucinous carcinoma. Methods: The clinical and pathological characteristics of 7 cases of ovarian seromucinous carcinoma were analyzed. Immunohistochemical study of selected markers was performed employing the EnVision method. Literature of ovarian seromucinous carcinoma were also reviewed. Results: The age of the 7 ovarian seromucinous carcinoma patients ranged from 27 to 70 years of age (mean=48 years). Two patients had bilateral ovarian tumors. The complaint of most patients was abdominal distention. The serum concentration of CA125 and/or CA19-9 was elevated in most patients.Four patients were found to have ascites during surgery, of whom 2 were also found to have malignant cells in their ascites or peritoneal washings. The maximum dimension of these tumors ranged from 6.0 to 15.0 cm (mean=9.3 cm). Grossly, 6 of 9 tumors were predominantly cystic with protrusions of papillae from the inside wall of the cysts. Among these 6 tumors, 2 had brown viscous material in the cyst. The other 3 tumors were predominantly solid. Microscopically, all 9 tumors contained endocervical-like mucinous cells and other Mullerian cells. The tumor cells had intermediate or severe atypia. A lot of acute inflammatory cells especially neutrophil polymorphs could be seen in the stroma and lumens of all the 9 tumors, which is an apparent feature for ovarian seromucinous tumors. Architecturally, the tumors mainly exhibited complex papillary architectures, compactly back-to-back glandular lumensforming cribriform, labyrinthine formations, or solid growth pattern, with immunophenotype of Mullerian tumors. Mucin stain was performed in 1 tumor with AB positive, PAS positive and D-PAS positive, highlighting intracytoplasmicmucin secretions. Follow-up (3-86 months with a mean of 21 month) data revealed that except 1 patient dying of the tumor at 81 months after surgery, the other 6 patients all survived the malignancy. Conclusions: Seromucinous carcinoma of the ovary possesses relatively special clinicopathologic features, with some morphological and immunophenotypical overlap with endometrioid carcinoma and low grade serous carcinoma of the ovary. It is necessary to thoroughly investigate the pathogenesis and molecular changes involved in the type of tumor to determine whether it is a convincingly distinctive category of ovarian carcinoma.