Retrospective pathologic review of 636 breast carcinomas from 611 patients revealed twelve tumors which were pure low grade tubular carcinoma (TC) and nineteen tumors with features combining both low grade tubular carcinoma and invasive duct carcinoma (T&D). A control group of 23 cases consisted of invasive duct carcinoma with at least a third of the tumor surface area showing tubular formation, but without the low grade features of tubular carcinoma. Life table analysis at 15 years showed a 100%, 72%, and 33% survival for TC, T&D, and controls, respectively. Eight percent of TC and 21% of T&D had axillary metastases compared to 67% for controls. Axillary metastases had no detrimental effect on TC or T&D survival. There were no recurrences in the TC group. Patients with T&D with tumor diameter 1.0 cm or less with 50% or greater low grade tubular carcinoma component are alive and well. The mean age of T&D was 7 years greater than TC. The combined TC and T&D group showed a significant incidence of multiple cancers in the ipsilateral breast and a significant trend toward bilateral cancers when compared to controls. Tubular carcinoma has an inherently low malignant potential with a histological and biological spectrum.