A review of the clinical and pathological features of 30 lactating nod
ules which were retrieved over the period 1975-1991 was undertaken. Cl
inically, 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 n
odule occurrence and ethnic background. Morphologically, a pre-existin
g underlying lesion was readily recognized in 18 cases. Seven fibroade
nomas, five tubular adenomas, two of which were infarcted, and six bre
ast hamartomas were identified. The other 12 cases were well circumscr
ibed nodules with a variable degree of inflammation and lobular hyperp
lasia. It is best to recognize these lesions as a heterogeneous group
and designate them as lactating nodules, noting any underlying patholo
gical process rather than using the older term lactating adenoma which
implies a single neoplastic entity.