From Detection to Decision: A Single-Center Analysis of Preoperative Imaging, Surgical Indications and Postoperative Histopathological Findings in Adrenal Lesions

Background/Objectives: The aim of this retrospective study was to characterize the preoperative hormonal, biochemical, and imaging features of adrenal lesions (ALs) and to assess differences in these features between benign and malignant lesions. Methods: This was a retrospective, single-center observational study conducted at the Endocrinology Clinic of Ankara Bilkent City Hospital. We reviewed the medical records of all patients referred to our clinic for the evaluation of an AL between February 2019 and August 2025. Demographic and clinical data and initial imaging were extracted from electronic medical records. Results: A total of 157 patients who underwent adrenalectomy were included in the analysis. Of these, 98 patients were female (62.4%) and 59 were male (37.6%). The mean age of the patients was 51.2 ± 12.54 years. Functionally, the findings were pheochromocytoma (n:44), overt Cushing syndrome (n:17), mild autosomal cortisol secretion (n:29), primary hyperaldosteronism (n:18), and non-functional (n:47). One patient had pheochromocytoma and mild autosomal cortisol secretion, and one patient had overt Cushing syndrome and primary hyperaldosteronism. Of the adrenal lesions, 70 (44.6%) were on the right, 71 (45.2%) on the left, and 16 (10.2%) were bilateral. 9% (7/79) of lesions measuring 4 cm and above, and 14% (4/28) of lesions measuring 6 cm and above were found to be malignant. The malignancy rate was 22% (4/18) in lesions located on the right and measuring 6 cm and above. All adrenocortical carcinomas were larger than 4 cm (8.3 ± 3.46) and all were on the right. The highest-grade malignant epithelial tumor was 12.9 cm and on the right. The malignant pheochromocytoma was 5.2 cm and on the left. It was determined that the frequency of right adrenal localization was significantly higher in the malignant group (85.7%) compared to the benign group (42.7%) (p = 0.045). Right tumor diameter (p = 0.002) and right and/or left tumor diameter (p < 0.001) were significantly higher in malignant lesions compared to benign lesions. Logistic regression analysis also supported a significant relationship between tumor size and malignancy. Conclusions: In our study, 9% (7/79) of lesions measuring 4 cm and above, and 14% (4/28) of lesions measuring 6 cm and above were found to be malignant. The malignancy rate in lesions on the right side measuring 6 cm and above was determined to be 22% (4/18). Although benign masses constituted the majority of lesions measuring 4 cm and above, all adrenocortical carcinomas were above 4 cm (8.3 ± 3.46). In light of the current findings, tumor size was observed to be associated with the distinction between malignant and benign adrenal lesions and may be considered an important descriptive characteristic in the clinical assessment of adrenal lesions.