8712 Pediatric Adrenocortical Oncocytic Neoplasm With Central Precocious Puberty: A Case Report

Abstract Disclosure: C.H. Huzita: None. W.M. Lins: None. S.K. Beeby: None. R.I. Lopes: None. F.T. Denes: None. A. Latronico: None. M. Polo: None. C.R. Victor: None. A.A. Hoff: None. B.B. Mendonca: None. M.Q. Almeida: None. M.C. Fragoso: None. Background: Adrenocortical oncocytic tumors (AOT) originate from the adrenal cortex. In the pediatric age group, they are rare and usually non-functional. Less than 20 cases of functional AOT have been reported and only one developed central precocious puberty. We describe the case of a patient with Li Fraumeni syndrome with germline TP53 pathogenic variant (PV) (p.R337H) who developed functional AOT and then central precocious puberty. ClinicalCase: A 2-year and 9-months old girl presented with pubic hair (Tanner stage P3S1) and clitoromegaly (2.6cm). Hormonal study showed elevated total testosterone (70ng/dL,ref. < 48ng/dL), DHEA-S (13490 ng/mL,ref<194 ng/mL) and a positive overnight 1mg dexamethasone suppression test (Cortisol5,8µg/dL). Abdominal ultrasonography showed a right round adrenal mass, which on magnetic resonance imaging (MRI) was well defined (50mm) and there was no evidence of invasion into adjacent organs or vessels. ChestX-ray and liver ultrasound imaging were normal.TheTP53 p.R337HPV was inherited from her father. The patient underwent a right adrenalectomy and oncocytic adrenocortical tumor was identified by histopathology (Biseglia score2/7, Wieneke score1/9 and Weiss score 5). Immunohistochemistry was positive for p53 and Ki67(13%). Following surgical removal of the tumor, the patient subsequently developed hypothalamic-pituitary activation and demonstrated central precocious puberty (Tanner P3S2 and advanced bone age). She was treated with a gonadotropin-releasing hormone agonist. Hormonal and clinical follow up demonstrated delayed pubertal progression. Discussion: AOT rarely presents with excess hormonal production. Herein we describe the case of the youngest child with functional AOT that developed central precocious puberty after the removal of the tumor. The mechanisms that cause hypothalamic-pituitary activation are not well understood, but prolonged exposure to androgen and then its withdrawal might lead to activation of hypothalamic GnRH pulse generated via a feedback system that has matured during the period of exposure to sex steroids.Therefore, clinical follow up of potential secondary effects of excess hormone secretion after tumor removal is important in pediatric patients with virilizing arenocortical tumor. In addition, considering Li Fraumeni syndrome, the screening of other tumors according to the Toronto protocol is required. Presentation: 6/2/2024