Following Low Dose Methotrexate
Therapy for Rheumatoid Arthritis in a 48-Year-Old Man
Benign proliferation of glandular tissue in the male breast is a common disorder.
Approximately one third of normal adult men are affected, most often after 50 years of age [1]. Some pathologic cases of breast enlargement are the result of renal , hepatic, nutritional, or endocrine dysfuction, and several drugs have also been implicated in the origin of gynecomastia [2]. Methotrexate (MTX) is the disease modifying antirheumatic drug, most frequently used for rheumatoid arthritis (RA) and psoriatic arthritis.
Although MTX is generally well tolerated, it has some side effects; mainly on the central nervous system, liver, blood, and lungs. Several cases of sexual dysfunction
(diminished libido, sexual impotence) [3] and gynecomastia [4] in men with RA receiving MTX treatment have been reported. Fibroadenoma is extremely rare in the male breast. It is explicable considering the absence of lobules in the normal male breast.
A variety of drugs, including MTX, can, at levels or durations beyond that required for the development of gynecomastia, induce formation of lobules in the male breast. These drugs may, therefore, predispose to the development of fibroadenoma. We recently observed one patient who was RA treated with low dose methotrexate (MTX) and who developed fibroadenoma in gynecomastia. There was no cause other than MTX found, despite extensive investigation. To our knowledge, there are no previous report of fibroadenoma in gynecomastia following low dose MTX therapy for RA.
Case Report
A 48-year-old man, with a 4-year history of seropositive RA, was treated with sodium aurothiomalate (GSTM) for only 3 months because of cutaneous intolerance. Dpenicillamine was tried but discontinued a few months later because of poor efficacy.
Oral MTX, 10 mg weekly, was then started. Six months later he complained of tenderness in the