Medullary Carcinoma of the Breast Reclassification by Ridolfi's criteria

Kim, Sung Won; Park, In Ae; Chang, Myung Chul; Kang, Hee Joon; Noh, Dong Young; Youn, Yeo Kyu; Oh, Seung Keun; Choe, Kuk Jin

Abstract

PURPOSE: A medullary carcinoma of the breast (MC) is a rare disease that hae a better prognosis than an infiltrating ductal carcinoma of no special type. An MC creates diagnostic difficulties, and there are numerous controversies associated with the histopathological definition of this special type of breast cancer. Among many criteria, Ridolfi's criteria seems to be the strictest and to give a more reliable prognosis. METHODS: We analyzed 2,953 primary breast carcinomas treated between Jan. 1981 and Jan. 2000. Thirty-seven patients previously defined as having an MC were reclassified by one pathologist using Ridolfi's criteria. The mean follow-up period was 62.7 months (range: 4 to 162 months), and hospital records were reviewed retrospectively for clinical information. RESULTS: Of the 37 treated patients, 24 (64.9%) were reclassified as having a typical medullary carcinoma (TMC), 6 (16.2%) as having an typical medullary carcinoma, and 7 (18.9%) as having a non-medullary carcinoma (NMC). The diagnostic conversion rate was, 37.8% and 10 of 30 patients (33.3%) previously diagnosed with TMC were reclassified into other forms. TMC had the least chance and NMC had the highest chance for lymph-node metastasis, and this difference was marginally significant (p=0.069). TMC showed a better 10-year overall survival rate (p=0.01) and 10-year disease-free survival rate (p=0.09) than NMC. CONCLUSION: TMC has the least chance of lymph-node metastasis, and the best prognosis in MC. Because of the relatively high diagnostic conversion rate, physician should be careful about omitting adjuvant therapy for TMC.