Endocrine Abstracts

Background: Leydig cell tumors (LCTs) are the most prevalent hormone-secreting testicular tumors, but overall, a rare testicular tumor subtype. Surgery is the main therapy with a favorable prognosis. Nevertheless, the development of central precocious puberty after surgery of the tumor has been observed on rare occasions.

Case Report: An 8.5-year-old boy presented with symptoms of sexual precocity dating back to 4 years. He had pubic hair (P4), enlarged left testis (G3: right testis 4 cc, left testis 10 cc with a palpable nodule), and stature advance. The hormonal evaluation revealed high levels of testosterone and estradiol and low levels of FSH and LH. Ultrasound of the testis showed an inhomogeneous hypoechoic tumor of the left testis. An inguinal radical orchiectomy managed this mass. The pathological diagnosis was a benign LCT. Three months after surgery, the patient presented persistent physical signs of sexual precocity, enlarged right testis, and stature gain of 8.5 cm. His hormonal values confirmed central precocious puberty: the testosterone level stayed high at 2.57 ng/ml facing LH and FSH levels at 3.26 UI/l and 4.55 UI/l respectively. Ultrasonography ruled out testicular tumor recurrence and brain magnetic resonance imaging excluded a tumor of the hypothalamus or pituitary gland. We started treatment with triptorelin (GnRH analog). After 3 months of treatment, we observed clinical regression of physical signs and stabilized growth velocity. After 6 months, hormonal assessment showed testosterone returned to prepuberal range (0.15 ng/ml), FSH and LH levels were 0.11 UI/l and 0.43 UI/l respectively. At the last follow-up (1 year from the beginning of triptorelin), we note a stature gain of 2 cm and a stabilization of the bone age with no adverse effects.

Discussion and conclusion: Eleven other cases of gonadotropin-dependent precocious puberty after successful treatment of LCTs have been reported in the litterature^1,2,3. The mechanism is unknown but is hypothesized due to the rebound secretion of LH after surgery of LCTs and subsequent reduction in androgens, which suppressed the adenohypophysis. The true incidence of central precocious puberty remains unclear because long-term follow-up of children with LCTs is not available. GnRH analog therapy appears to be the most effective medical treatment in such cases.

Keyboards: LCTs, central precocious puberty, GnRH analog.

References: 1. Akilan K et al. Can Urol Assoc J. 2020;14(7): E343-E346.

2. Verrotti A et al, Front Pediatr. 2015 Nov 2;3:93.

3. Luckie TM et al, J Pediatr Hematol Oncol. 2019 Jan;41(1):74-76.