Mixed corticomedullary tumor of the adrenal gland: pheochromocytoma associated with cortical adenoma (case report)

Mixed corticomedullary tumor of the adrenal gland is an extremely rare tumor characterized by a combination of steroidogenic and chromaffin cells in a single tumor mass simultaneously producing adrenocortical hormones and catecholamines. Sometimes, it is associated with ectopic production of adrenocorticotropic hormone (ACTH). The tumor development mechanisms are underinvestigated. The paper is focused on a clinical case of a 53-year-old patient with initial complaints of hypertension, tachycardia, and hyperhydrosis. A laboratory testing revealed increased urinary free methanephrine levels associated with a lack of adequate suppression of cortisol production in a 1-mg dexamethasone suppression test and persistent circadian rhythm of cortisol secretion. ACTH level was not suppressed, and plasma renin and aldosterone levels remained within the reference range. According to 18F- DOPA whole-body positron emission tomography, a left adrenal gland neoplasm characterized by DOPA hypermetabolism was revealed. Based on the examination data, the patient was diagnosed with pheochromocytoma and underwent a surgery (i.e., laparoscopic left adrenalectomy). A histological examination demonstrated a corticomedullary tumor of the adrenal gland (pheochromocytoma associated with a cortical adenoma). Immunohistochemistry showed 10% of ACTH-positive tumor cells on the pheochromocytoma periphery. This caused a lack of an adequate decrease in blood cortisol levels in a 2-mg dexamethasone suppression test. Keywords: mixed corticomedullary tumor, adrenal adenoma, pheochromocytoma, corticosteroma, autonomous cortisol production, laparoscopic adrenalectomy. For citation: Vyazitskaya M.V., Belousova L.V., Karonova T.L., Tsoi U.A., Grineva E.N. Mixed corticomedullary tumor of the adrenal gland: pheochromocytoma associated with cortical adenoma (case report). RMJ. 2025;2:31–34. DOI: 10.32364/2225-2282-2025-2-6