Synchronous Adrenocortical Carcinoma, Renal Cell Carcinoma, and Mediastinal Mature Teratoma with Heterozygous Variants in SMARCA4, APC, and MYBP3: A Case Report

Abstract

We describe an exceptionally rare case of a 46-year-old woman diagnosed with three synchronous primary tumors: adrenocortical carcinoma (ACC), renal cell carcinoma (RCC), and an anterior mediastinal mature teratoma. Cross-sectional imaging demonstrated distinct lesions of comparable size (each measuring 6-7 cm) in the right adrenal gland, right kidney, and the mediastinum. The patient underwent radical nephrectomy, adrenalectomy, and excision of the mediastinal mass. Histopathology confirmed clear cell RCC, ACC, and a mature teratoma without malignant transformation. Molecular testing revealed heterozygous variants in SMARCA4, APC, and MYBP3, suggesting a permissive background for multiple tumorigenic events. Importantly, all tumors were diagnosed at an early stage and completely resected, thereby enabling curative surgery without the need for adjuvant therapy. This unique presentation underlines the importance of integrated radiological, pathological, and molecular evaluation in patients with multiple synchronous tumors and highlights the role of vigilant follow-up in long-term management. Copyright © 2026 The Author(s). Published by Galenos Publishing House on behalf of Turkish Society of Medical Oncology. Licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 (CC BY-NC-ND) International License.