SUN-LB052 Sexual Precocity in a Male Toddler Caused by Inadvertent Prolonged Exposure to Exogenous Testosterone

Abstract

Background: Unintentional exposure to cutaneous androgen products leading to virilization has previously been described in children, however, continues to be an overlooked cause of precocious sexual development. Clinical Case: A 16-month-old boy presented for a second opinion consultation regarding sexual precocity. Parents noticed enlargement of his penis and appearance of sparse pubic hair at about 4 months of age, prompting referral to an endocrinologist by 10 months. A comprehensive evaluation was performed. The bone age was advanced at 13-15 months and his total testosterone was 243 ng/dL (normal < 20 ng/dL). An ACTH stimulation test was negative for disorders of steroid biosynthesis. Ultrasound examination showed normal testes and no evidence of adrenal or hepatic masses. A Lupron stimulation test, performed at 14 months of age, showed a peak LH of 1.41 mIU/mL (normal < 5 mIU/mL) and peak total testosterone of 21 ng/dL (reference range ≤ 5 ng/dL). The patient was diagnosed with familial gonadotropin-independent male-limited sexual precocity, a rare condition caused by activating mutations of the LHCGR (luteinizing hormone/choriogonadotropin receptor) gene. Treatment with bicalutamide and anastrozole was prescribed. Owing to parental concern about side effects of the prescribed medications, they did not start the recommended treatment and sought a second opinion. On exam, his length was > 99th percentile for age, stretched penile length 7.5 cm (mean ± standard deviation for this age: 4.82 ± 0.44 cm), mid-shaft diameter 2 cm, and testes 2 mL bilaterally. The scrotum was thin and pendulous and there were a few pubic hairs at the base of the penis. His total testosterone was < 10 ng/dL, LH < 0.1 mIU/mL, and hCG < 0.1 mIU/mL (all normal). Ultrasound of the testes was normal. After the visit, a more thorough history was obtained from the mother. She remembered that the child’s maternal grandfather, who provided direct care to the patient in the first year of life while she attended school, used transdermal testosterone gel daily for treatment of hypogonadism. Since the grandfather’s absence after the patient’s first birthday, the child has not had any further progression of his secondary sex characteristics. On follow-up visit at 17 months of age, patient’s exam was stable. Genetic testing for mutations of the LHCGR gene was negative. Conclusion: Exogenous exposure to transdermal androgens should be kept high on the differential diagnosis for children presenting with evidence of peripheral sexual precocity as it can save patients unnecessary and costly work-up and intervention. Physicians should also be aware of their own anchoring biases, especially when evaluating patients for a second opinion of rare diagnoses. Lastly, adult endocrinologists should be mindful in counseling patients prescribed topical testosterone agents about the risk of cutaneous exposure to female partners and children. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.