A4 ½-YEAR-OLD boy presented with signs of precocious puberty (Figure 1). During the last year, he had grown 20 cm. He seemed to be older than his stated age and had upper lip hair and early acne. His penis was large (9 cm long) with increased pigmentation, and pubic hair was present. The left testis was slightly larger than the right (5 cm3 vs 4 cm3). His bone age was 7.1 years.
Microscopic sections from the left testis are shown in Figure 2.
Denouement and Discussion
Precocious Puberty Caused by a Leydig Cell Testicular Tumor
Testicular tumors comprise almost 1% of childhood tumors; of these, approximately 1.5% are Leydig cell–type tumors.1 In adults, 2% to 3% of testicular tumors are of the Leydig cell type. Leydig cell and granulosa cell tumors are the most frequent gonadal tumors inducing precocious puberty in the 2 sexes.2 Since 1895,