Case Report: Androgen-secreting pediatric adrenocortical tumor of uncertain malignant potential presenting with virilization in a 19-month-old girl.

Background: Virilization in girls younger than 2 years should prompt careful evaluation for pathological androgen excess and should be interpreted as a practical clinical reminder rather than as a stand-alone diagnostic tool. Pediatric adrenocortical tumors (ACTs) are rare but are usually hormonally active, and their interpretation requires pediatric-specific clinicopathological criteria rather than direct application of adult adrenal carcinoma criteria. Case presentation: A 19-month-old girl presented with a 6-month history of progressive voice deepening, pubic hair growth, and clitoromegaly. Beard-like facial hair, acne, axillary hair, adult-type body odor, and vaginal bleeding were not reported. Basal gonadotropins were suppressed, gonadotropin-releasing hormone analogue stimulation showed a non-pubertal luteinizing hormone response, bone age was advanced, and dehydroepiandrosterone sulfate was markedly elevated (>1,000 μg/dL; above the assay upper reportable limit). Imaging identified an approximately 5-cm right adrenal mass. The patient underwent open surgical resection. Histopathology showed an ACT of uncertain malignant potential with a formally reported Wieneke score of 3, based on increased or borderline-high mitotic activity as interpreted in the pathology report, atypical mitotic figures, and capsular invasion. Immunohistochemistry showed steroidogenic marker expression, a missense-mutant p53 pattern, focal reticulin rarefaction, and a Ki-67 hotspot index of approximately 30%. Postoperative androgen levels declined markedly, and biochemical remission was maintained at 4 and 8 months. Discussion: Androgen-dominant virilization preceded and outweighed mild breast development, serving as a practical reminder to prioritize adrenal-focused assessment in very young girls with rapidly progressive virilization. Preoperative ultrasonography, contrast-enhanced computed tomography, and magnetic resonance imaging were performed; dedicated postoperative contrast-enhanced abdominal CT or MRI had not yet been obtained during the available follow-up period. Genetic testing was incomplete because the family declined germline testing after counseling; testing of the proband should be re-offered during follow-up, with cascade testing for first-degree relatives if a pathogenic germline variant is identified. Conclusion: Long-term surveillance should include endocrine assessment, pubertal monitoring, genetics re-counseling, and protocolized cross-sectional imaging, because early biochemical remission does not exclude recurrence or later secondary central precocious puberty.