Thymus and breast cancer--plasma androgens, thymic pathology, and peripheral lymphocytes in myasthenia gravis.

Plasma androgen sulfates were measured in 92 patients with myasthenia gravis. Plasma androgen sulfates were strongly associated with thymic pathology. The presence of germinal centers was associated with decreased androgen levels. A weak but significant positive correlation existed between androgen sulfates and lymphocyte counts. Low lymphocyte counts in patients with germinal centers were associated with subnormal androgen concentrations. Plasma androgen sulfate levels decreased immediately after thymectomy, but overall no significant differences were found between prethymectomy and post thymectomy levels. A trend toward higher concentrations of plasma androgens was noted 5 or more years post thymectomy. Plasma androgen sulfate levels in myasthenia gravis patients with breast cancer were markedly depressed. The lowest androgen sulfate levels were observed in patients who had previous bilateral breast cancer and those who, subsequent to the determination of the steroid sulfates, developed a second primary lesion of the breast.