Surgical implications of underestimation of adrenal tumour size by computed tomography

Abstract

Background: Size of adrenal mass is an important consideration during adrenal surgery, with regard to the choice of surgical approach and management of adrenaloma. The aim of the present study was to evaluate the precision of preoperative computed tomography (CT) on the size estimation of adrenal lesions and to review its potential implications on surgical decision making. Methods: Records of 110 patients who underwent adrenalectomy for various adrenal pathologies from 1981 to 1997 were reviewed retrospectively. Patients (n = 92) who had documented dimensions of adrenal mass by both preoperative CT and pathological examination were selected for analysis. Results: CT overall underestimated the actual size of adrenal lesions by 16 per cent compared with measurement of resected specimens (mean 3.1 versus 3.6 cm; P < 0.001). There was a significant underestimation of the actual size of adrenal lesions measuring less than 6 cm by CT but not for lesions larger than 6.0 cm. Phaeochromocytoma (n = 17) was the only pathological condition consistently underestimated by CT. Conclusion: Conventional CT overall underestimates the real size of adrenal lesions, in particular phaeochromocytoma and adrenal rumours of less than 6.0 cm in size. Surgical decision making based on size should take this limitation into account.