Ectopic adrenocortical adenoma in the renal sinus: A clinical case; Эктопическая адренокортикальная аденома в почечном синусе: клинический случай

Background. Adrenal ectopy is a congenital anomaly of the endocrine system. It occurs in less than 1% of the adult population. Ectopy lesions consist mainly of cortex and a minimal amount of medulla. Ectopic adenomas of the adrenal cortex are small, non-functional, asymptomatic, and usually found incidentally. They are found in the kidney only in 0.1-0.6% of observations. Aim. To present a rare case of non-functioning ectopic adrenocortical adenoma in the renal sinus. Results. A 56-year-old man underwent a routine medical examination, and an ultrasound showed a tumor in the renal sinus. According to X-ray computerized and contrast-enhanced magnetic resonance imaging (MRI), a soft tissue vascularized mass in the renal sinus on the right was found, 29×15×20 mm in size. The density on the Hounsfield scale was +15HU with heterogeneous contrast uptake (up to +75HU), and the mass was closely adjacent to the renal artery and vein. No abnormalities were detected in the adrenal glands. According to MRI, the tumor had a heterogeneous structure with a signal reduction in T2 mode with diffusion restriction. Morphological verification was impossible due to anatomical features. A nephrectomy was performed for suspected renal cell carcinoma of the renal hilum. In pathohistological examination, the tumor was represented by light and eosinophilic cells; immunohistochemistry revealed a pronounced expression of SF1, Melan A, and CYP11B2 biomarkers. Ectopic cortical adrenal adenoma in the renal sinus was diagnosed. The patient was examined in 3 months, and no recurrence or functional activity was detected. Conclusion. Ectopic adrenocortical adenoma in the renal sinus is extremely rare and usually non-functional. X-ray computed tomography and MRI are sensitive methods for localizing ectopic adrenal tumors. The density value of the mass in the native mode of 10-20 HU indicates a high intracellular lipid content. A surgical method is recommended for the treatment of functional and non-functional adenomas. The final diagnosis is established by histological and immunohistochemical examinations. © 2025 Elsevier B.V., All rights reserved.