Primary breast carcinomas from 192 patients treated between 1955 and 1965 for medullary carcinoma or duct carcinoma with medullary features were reviewed and reclassified using strictly defined pathologic criteria. Tumors that fulfilled requirements for medullary carcinoma were identified in 57 patients. Another 79 tumors that varied slightly from these criteria were termed “atypical” medullary carcinoma and 56 were characterized as nonmedullary carcinoma. When compared with the patients with nonmedullary infiltrating duct carcinoma, patients with medullary carcinoma had a significantly higher survival rate at 10 years, (84% vs. 63%), similar frequency of axillary lymph node metastases, and a more favorable prognosis when nodal metastases were present. Within the medullary carcinoma group, patients had a significantly better survival rate if their primary tumors were smaller than 3 cm in diameter. The average size of medullary carcinomas was 2.9 cm and that of nonmedullary carcinomas, 4.0 cm. Bilaterality was not more common in patients with medullary carcinoma, but the interval between diagnosis of the tumors was twice as long when one lesion was medullary (8.8 years) than when both were infiltrating duct carcinomas (4.6 years). Bilaterality was significantly more common among patients with medullary carcinoma who had a positive family history. The medullary lesion was most often the second one to be diagnosed. The 79 patients with atypical medullary carcinoma had a 10-year survival rate of 74%. Patients in this group whose tumors had a sparse lymphoid infiltrate had a relatively poor prognosis. Intraductal carcinoma at the periphery of the lesion was not associated with a less favorable prognosis. It was concluded that intraductal carcinoma was consistent with the diagnosis of medullary carcinoma if all other criteria for the diagnosis were satisfied. With these exceptions we were unable to draw any firm conclusions about favorable or unfavorable effects of other morphologic features on survival in the group with atypical medullary carcinoma. Until further study of this group reveals that some or all of the lesions form a distinct clinicopathologic entity they are best included under the heading of infiltrating duct carcinoma. When the criteria described in this report were used, medullary carcinoma proved to be a specific lesion associated with a significantly better prognosis than ordinary infiltrating duct carcinoma.
Ridolfi et al. (1977) studied this question.