Adrenocortical Carcinoma With Right Atrial Extension in a Three-Year-Old Child: A Case Report.

Pediatric adrenocortical carcinoma is a rare and aggressive malignancy frequently associated with germline tumor protein p53 (TP53) mutations and can mimic congenital adrenal hyperplasia (CAH). We present a three-year-old child with progressive virilization, initially presumed to be CAH, who presented in adrenal crisis with abdominal distention. Imaging revealed a large right adrenal mass, with the mass extending from the right hepatic vein through the inferior vena cava (IVC) and into the right atrium, causing an almost complete obstruction of the tricuspid valve. After evaluation and stabilization, urgent surgery was performed, where the intracardiac mass was successfully removed, but the adrenal tumor remained due to anatomical complexity. Postoperative evaluation revealed a near-normal return of cardiac function, while the adrenal tumor continued to progress, and multiple emboli continued to form. Genetic testing revealed a TP53 mutation consistent with Li-Fraumeni syndrome. This case highlights the difficulties in differentiating between adrenocortical carcinoma and CAH in children. The rare presence of intracardiac extension of the tumor increases the challenge in managing these cases.