Case of Adrenocortical Cancer Eleven Years After Diagnosis of Adrenocortical Adenoma

High-resolution imaging has increased the detection rate of adrenal gland neoplasms, necessitating changes in the management of patients with adrenal incidentalomas. Despite existing guidelines, the treatment strategy in patients with incidental adrenal gland neoplasms of <4 cm remains debatable. According to the updated EHS/ENSAT guidelines on incidentalomas (2023), benign neoplasms with ≤10 HU do not require further imaging examinations. For neoplasms of <4 cm with a native density of 11–20 HU, a follow-up examination after 12 months is recommended. This paper presents a clinical case of adrenocortical cancer with autonomous cortisol secretion, which originated from a nonfunctioning right adrenal gland neoplasm of <2 cm. The tumor was detected accidentally during abdominal and retroperitoneal ultrasound and computed tomography; however, malignant transformation did not occur until 11 years later. A comprehensive preoperative assessment, including biochemical and imaging examinations, confirmed that the patient was eligible for elective surgery. A pathological examination confirmed an oncocytic adrenocortical carcinoma (Ki-67: 40%).