[Diagnostic imaging in Cushing's disease and its correlation with postsurgical clinical course]

The purpose of this paper was to assess the accuracy of computed tomography (CT) and magnetic resonance (MR) in the preoperative identification of corticotropin-secreting pituitary adenomas and to evaluate the concordance with the postoperative outcome. A total of 44 images of patients with Cushing's disease were retrospectively taken into consideration; 23 CT and 29 MR were evaluated. Patients were subdivided into remission or persistence, following the postoperative outcome and biochemical tests. In 13 out of 23 CT performed, an adenoma was found, the remaining 10 being negative. TC sensitivity was 56.5%. Twenty five MR were positive and 4 were negative. The overall sensitivity of MR in detecting ACTH-secreting adenoma was greater (86.0%, P: 0.0373, after Yates correction). After operation, 31 patients (70.5%, Cl 0.70 +/- 0.13) were considered to be in remission (27 total remission and 4 partial remission); 23 had had preoperative visualization of the pituitary tumor and 8 negative neuroradiological evaluation. Thirteen patients had persistence of disease as shown by sustained hypercotisolism in biochemical tests. In 11 of these patients, an adenoma had been preoperatively identified whereas in the remaining 2 no evidence of tumor lesion had been detected. An histologically proven tumor was found in 33 patients but findings were negative in the remaining 11 cases. Lack of histological evidence of an ACTH-secreting adenoma was more frequent in patients with persistent hypercortisolism (P < 0.0078).

1) MR seems to be more sensitive than CT for detecting ACTH-secreting adenomas (P: 0.037, after Yates correction); 2) no relationship was disclosed between the absence of imaging signs of adenoma and the postsurgical outcome; 3) the remission rate was significantly higher in patients with positive than in those with negative histological findings.