Nodular breast lesions during pregnancy and lactation.

A review of the clinical and pathological features of 30 lactating nodules which were retrieved over the period 1975-1991 was undertaken. Clinically, the nodules occurred during any pregnancy and in subsequent pregnancies no further nodules developed. There were no favoured sites or lateralization of nodules, nor was there any correlation between nodule occurrence and ethnic background. Morphologically, a pre-existing underlying lesion was readily recognized in 18 cases. Seven fibroadenomas, five tubular adenomas, two of which were infarcted, and six breast hamartomas were identified. The other 12 cases were well circumscribed nodules with a variable degree of inflammation and lobular hyperplasia. It is best to recognize these lesions as a heterogeneous group and designate them as lactating nodules, noting any underlying pathological process rather than using the older term lactating adenoma which implies a single neoplastic entity.