Noninvasive, microinvasive, and invasive mucinous carcinomas of the ovary

BACKGROUND Whether ovarian mucinous tumors with epithelial stratification of more than three cell layers in the absence of stromal invasion (i.e., carcinomas diagnosed according to the Hart and Norris criteria) should be placed in the same category as mucinous tumors with stromal invasion (i.e., unquestionable carcinomas) remains controversial. Because individual mucinous tumors frequently contain benign, borderline, and malignant components, the adequacy of sampling has been emphasized. METHODS We examined 21 mucinous carcinomas with no destructive stromal invasion (MCNI), 4 mucinous carcinomas with microinvasion (MCMI) of < 2 mm, and 15 mucinous carcinomas with invasion (MCI) of ≥ 2 mm. Tumors were diagnosed as MCNI according to Hart and Norris criteria (12 tumors) or when severe nuclear atypia was present (9 tumors). Cases of MCNI were selected for review if a section had been taken for each 2 cm or less of the tumor's greatest diameter. The International Federation of Gynecology and Obstetrics stage and follow‐up data of each case were examined, and differences among MCNI, MCMI, and MCI were analyzed. RESULTS All 21 patients with MCNI and all 4 patients with MCMI had Stage I disease; there was no recurrence or death in these cases. In contrast, 7 of 15 patients with MCI had Stage II or III disease, and 8 patients died. CONCLUSION MCNI clearly should be distinguished from MCI and be classified as noninvasive carcinomas after the absence of destructive stromal invasion has been confirmed by examining a sufficient number of sections. Cancer 2000;89:1541–6. © 2000 American Cancer Society.