Unilateral Testicular Enlargement Resulting from Inapparent 21-Hybroxylase Deficiency

Abstract

A case is reported in which unilateral testicular enlargement was the only presenting sign in 21-hydroxylase deficiency of the acquired or adult onset type. Measurement of plasma 17-hydroxy-rogesterone throughout 24 h revealed marked elevations, mostly between 0400 and 0700 h. This steroid increased more than 18-fold 30 min following ACTH administration, confirming the diagnosis. Glucocorticoid therapy corrected the testicular endlargement. Inapparent 21-hydroxylase deficiency is a medically treatable cause of testicular enlargement that can be diagnosed by measurement of plasma 17-hydroxyprogesterone during a 30 min ACTH stimulation test.