Eighty-four patients included in the Juvenile Papillomatosis Registry were reviewed. The age of diagnosis ranged from 10-44 years (mean, 21). Sixty-nine percent of patients were less than or equal to 20 years of age. The left breast was affected slightly more often (52%) than the right (48%) when the lesion was unilateral. Two patients had bilateral lesions. Patterns of menarche, marital history, parity, and use of birth control pills were not exceptional for women in this age group. No instance was found of maternal use of estrogens during pregnancy. There were no instances of carcinoma developing after biopsy of juvenile papillomatosis, but a newly diagnosed patient had secretory carcinoma arising from juvenile papillomatosis. Two other examples of concurrent carcinoma were previously reported (ipsilateral lobular carcinoma in situ and contralateral secretory carcinoma). Particularly noteworthy is the finding that 26% of patients wih information available reported that breast carcinoma had occurred in one or more female relatives. The major were older, secondary relatives (grandmothers, great aunts), although maternal breast carcinoma (five cass) was also reported. The mothers of both girls who had secretory carcinoma associated with juvenile papillomatosis had been treated for breast cancer. These findings, based on incomplete reporting, are cause for concern in two respects: the findings suggest that juvenile papillomatosis may be a marker for breast cancer for the patient's family, and they indicate a need for continued long-term follow-up of juvenile papillomatosis patients who may themselves be at increased risk.