Prognostic significance of adrenal gland morphology at CT in patients with three common malignancies.

Objectives: To determine whether minor alterations in adrenal gland morphology at baseline CT in three common cancers indicate early metastasis. Methods: 689 patients (237 with lung cancer, 228 with breast cancer, 224 with melanoma) underwent baseline and follow-up CTs that included the adrenals. Two readers independently scored each adrenal at baseline CT as normal, smoothly enlarged, nodular or mass-containing. Adrenals containing a mass >10 mm were excluded. The appearance of each adrenal on the latest available CT was assessed for change since baseline. Cox models were used to assess the association between adrenal morphology at initial CT and subsequent development of adrenal metastasis (defined as new mass >10 mm, corroborated by follow-up imaging). kappa statistics were calculated to assess inter-reader agreement. Results: Initial and follow-up CT evaluations were recorded for 1317 adrenals (median follow-up, 18.6 months). At initial CT, Readers 1 and 2 interpreted 1242 and 1230 adrenals as normal, 40 and 57 as smoothly enlarged, 29 and 25 as nodular, and 6 and 5 as containing masses >10 mm, respectively. kappa-values were 0.52 (moderate) at initial CT and 0.70 (substantial) at follow-up. The hazard ratio for developing a metastasis at follow-up CT given an abnormal adrenal assessment at baseline was 0.7 [95% confidence interval (CI) 0.2-2.1; p=0.47] for Reader 1, and 2.0 (95% CI 0.8-4.7; p=0.12) for Reader 2. Conclusion: Minor morphological abnormalities of adrenals at initial CT did not represent early adrenal metastasis in most patients in this population.