Penicillamine induced mammary hyperplasia: report of a case and review of the literature.

A 41-year-old woman with rheumatoid arthritis developed massive breast enlargement while taking penicillamine. Her endocrine evaluation was unremarkable, and the breast enlargement resolved with danazol therapy. Penicillamine may increase breast tissue sensitivity to steroid hormones in some patients, resulting in breast growth. This rare complication resolves spontaneously in men, but in women reversal of breast enlargement requires androgen therapy.