Juvenile papillomatosis of the breast ("Swiss cheese disease") is a benign localized proliferative condition of the breast which occurs almost exclusively in young adult women. Patients with this lesion often have a family history of breast carcinoma, and rarely carcinoma may coexist with the lesion at the time of diagnosis. We present two cases of male infants with juvenile papillomatosis of the breast. The pathology and clinical management of this novel lesion is discussed.