Mucinous neoplasms associated with mature cystic teratomas: A clinicopathologic study of 50 cases: Are we ready for nomenclature change?

Mucinous neoplasms associated with ovarian teratomas (MOvNTs) are uncommon with only a few large series published thus far. Their clinicopathologic features are evaluated in this multi-institutional study. Fifty MOvNTs were retrieved from the files of four institutions over 16-years (yr). Patient age, CEA and CA-125 levels, laterality, tumor size, type of mucinous tumor (according to gynecologic pathology criteria and proposed appendiceal nomenclature when applicable), immunohistochemistry (IHC), FIGO stage, presence of pseudomyxoma ovarii and peritonei, treatment, follow-up in months (mos), and outcome were recorded. Patients ranged in age from 17 years to 74 years (mean 43, median, 42). Increased CA-125 levels correlated with mucinous carcinoma and mucinous borderline tumor (p=0.0270), and CEA correlated with mucinous carcinoma (p=0.0256). Mucinous neoplasms were either cystadenomas (16), borderline tumors (20) or carcinomas (14). Forty-one were Mullerian/surface epithelial type and 9 were appendiceal-like. Using appendiceal nomenclature: Seven were low grade mucinous appendiceal neoplasms and 2 high grade appendiceal neoplasms. IHC: 39 % were CK20/CDX2/SATB2 positive and 61 % were CK7 > CK20 (+), and SATB2-. Almost all patients presented with FIGO stage I disease; except one each with FIGO II and IIIC disease. All patients had surgical resection, and 10 patients had adjuvant therapy. Recurrences occurred in 4 patients (range: 10-84 mos). At last follow-up (median 60 mos): 33 patients had no evidence of disease, 3 died of disease, 1 was alive with disease, 2 died of other causes, and 11 were lost to follow-up. MOvNTs are usually Mullerian/surface epithelial type and FIGO stage I. As the only patients with adverse outcome were those who had a diagnosis of mucinous carcinoma or microinvasive carcinoma, whether of appendiceal-like or Mullerian/surface epithelial type, using established gynecologic, rather than GI criteria for classifying all types of MOvNTs is recommended.