Incidentally detected adrenal tumours (incidentalomas): histological heterogeneity and differentiated therapeutic approach

Abstract

To find a differentiated therapeutical approach to incidentalomas. Prospective study of incidentalomas: their histology, hormonal activity, and growth if primarily non-operated. Admissions to an academic tertiary care centre because of incidentaloma. Thirty-eight female, 25 male, 27-85 years old. Ultrasound, computed tomography and adrenal scintigraphy when appropriate; investigations to exclude malignancy giving metastasis into the adrenal gland; ACTH, cortisol, aldosterone, renin activity, androgene, catecholamine measurements; surgery or follow-up. Rate of malignancy; linkage of tumour size to probability of malignancy; prevalence of tumours with subtle hormone excess. Cortical adenomas occurred in 13/31, metastases in 7/31 of the histologically confirmed cases. In 10/31 cases, the computed tomography indicated a size that was smaller than the pathological size (mean = 20 mm). 20.6% of all incidentalomas and 61.5% of the 13 operated corticol adenomas showed subtle hormonal activity. Twenty-seven incidentalomas < 30 mm were followed-up (3-41 months; mean 18 months) and showed growth in only one case. Sensitivity, specificity, and predictive value (PV) of a tumour > or = 30 mm to indicate malignancy were: 1.0, 0.56 and 0.27, respectively. The PV of a < 30 mm tumour to exclude malignancy was 1.0. Oncological screening tests are necessary in all incidentalomas. Tumours > or = 30 mm should be operated but smaller ones can be followed-up, because they are usually benign and rarely show progressive growth. Cortical adenomas with subtle hormonal overproduction and hypertension, diabetes or osteoporosis should be operated, irrespective of their size, but in the absence of relevant clinical symptoms they can be followed-up.