Testicular Leydig Cell Tumor in a Child With Secondary GnRH-Dependent Precocious Puberty Before Surgery: A Case Report With a Review of Clinical Characteristics From 24 Pediatric Cases in Japan

<p>We report the case of a 10-year-old boy who presented with secondary GnRH-dependent precocious puberty caused by a testicular Leydig cell tumor. He was initially followed up by the pediatric endocrinology department with the diagnosis of mental retardation and growth hormone deficiency. At 9 years and 10 months of age, a rapid increase in height, skeletal growth acceleration, and penile growth was seen. He was hospitalized for examination at the previous hospital. He was diagnosed with GnRH-dependent precocious puberty and referred to our department with the suspicion of a testicular tumor. Testicular ultrasonography showed a hypoechoic left testicular mass with a diameter of 10 mm. Positron emission tomography-computed tomography revealed an accumulation of fluorodeoxyglucose in the left testicle, and the undeniable presence of malignancy. Therefore, a left orchiectomy was performed. The pathological diagnosis was a Leydig cell tumor; however, there were no histopathological features of malignancy. There are few pediatric case reports of Leydig cell tumors in Japan; this is the 24th reported case. Furthermore, this is the first case in which GnRH-dependent precocious puberty was diagnosed before surgery. We reviewed the clinical characteristics of previous Japanese pediatric case reports and concluded that pediatric Leydig cell tumor should be differentiated when prepubertal overgrowth symptoms are observed. Early diagnosis could be expected by performing testicular ultrasonography.</p>