Is adrenal tumor size related to evolution time or does it represent a biological difference?

Abstract

Adrenal tumor (AT) malignancy has been related to tumor size. Since laparoscopic surgery is being used, smaller adrenal tumors are being excised. To evaluate eventual clinical and histological differences between adrenal tumors smaller than 4 cm. and those larger than 6 cm. Retrospective review of pathological reports and clinical records of patients operated for adrenal tumors, dividing them in two groups. Group 1 had 29 patients aged 52 +/- 13 years with AT < 4 cm operated during the period 2000-2005, and Group 2 was formed by 52 patients aged 46 +/-18 years with AT >6 cm operated between 1984-2005- Tumors between 4 and 6 cm were not included in the study to establish clear cut differences between groups. Tumors were functional in 40 and 41% of cases in groups 1 and 2 respectively. Fifty percent of functional tumors of group 1 were pheochromocytomas and the rest secreted aldosterone. In group 2, 66% of tumors were pheochromocytomas and no aldosterone secreting tumors were found. Fifty two and eight percent of tumors in Groups 1 and 2 were adenomas, respectively (p <0.001). Nineteen tumors of group 2 were malignant, compared with one of group 1 (p <0.001). The tumor size of adrenal cortical tumors may represent biological differences, suggesting two different tumor populations. At time of diagnosis adrenal carcinomas are almost always larger than 6 cm.