OBJECTIVETo investigate the correlation between CT image presentations and biochemical indexes in adrenal adenomas and pheochromocytomas.

METHODSWe retrospectively analyzed the CT features, cortisol rhythm, supine and orthostatic hypertension and 24-h urine methoxy in 209 patients with benign adrenal tumors. The relationship between CT findings and the biochemical indexes were analyzed in patients with different benign adrenal tumors.

RESULTSThe 209 cases analyzed included 53 cases of cortisol adenoma, 65 cases of aldosterone adenoma, 45 cases of non-functional adenoma and 46 cases of pheochromocytomas. The plain CT scan values of the 4 groups were 17.25 ± 1.81, 14.52 ± 1.57, 12.20 ± 2.05, 42.42 ± 0.97 HU, enhanced CT values (arterial phase) were 47.82 ± 3.07, 39.23 ± 2.37, 45.35 ± 6.46, and 104.93 ± 5.84 HU, respectively, and the differences between CT scan and enhanced CT values were 30.58 ± 2.29, 24.71 ± 1.55, 33.15 ± 5.18, and 62.51 ± 5.73 HU, respectively. In cortisol adenoma group, cortisol levels measured at 16:00 and 24:00 were positively correlated with plain CT scan value (r=0.506, P=0.0001; r=0.504, P=0.0001) and enhanced CT value (r=0.514, P=0.0001; r=0.554, P=0.0001). In pheochromocytoma group, plain scan CT value and the difference between plain and enhanced CT scan value were correlated with 24-h urine methoxy adrenaline (Rho;=0.342, 0.350; P=0.020, 0.017, respectively) and norepinephrine (Rho;=0.419, 0.412; P=0.004, 0.004, respectively).

CONCLUSIONPlain and enhanced CT scan values and their combination have important value in differential diagnosis of adenoma and pheochromocytoma tumor, CT values combine with biochemical indexes can reduce misdiagnosis and missed diagnosis of pheochromocytoma.