Figure 5

A 4-year-old male with a history of asthma presented with complaints of pubertal changes (pubic hair growth, erections, sexual behaviors, acne, deepening of the voice, accelerated linear growth, and increased muscle mass). (a) On examination, he had an enlarged penis and Tanner III-IV pubic hair; testes were minimally enlarged (b) Bone age was 10 years and laboratory evaluation revealed a total testosterone of 673 ng/dL (normal ≤5), β-hCG of 22.9 mIU/mL (normal ≤1.0), and undetectable gonadotropin levels, consistent with hCG-mediated sexual precocity. (c) CT chest revealed a 2.7×2.5 cm heterogeneous mass located in the anterior mediastinum (arrows). This lesion was resected and confirmed to be a mature cystic teratoma. After surgery, the patient's labs normalized, and he remains clinically prepubertal at a chronological age of 9 years and bone age of 13 years.