tuberculosis of the breast is an uncommon disease. the authors present a case of an asymptomatic 64 year-old patient whose mammography showed a right breast nodule which needed aetiological investigation. complementary diagnostic exams did not lead to a differential diagnosis between granulomatous lesion and breast carcinoma; nodule aspiration results suggested tuberculosis of the breast but were unclear and so tuberculosis antibiotics were initiated. no other tuberculosis infectious focus was found at clinical-laboratory evaluation. imagiology progress was favourable, so patient continued treatment. the authors highlight the low rate of primary tuberculosis of the breast and make a brief reference to the pathology, which has a low rate of microbiological and pathological-anatomical identification.