Quantitative and Morphological Assessment of Computed Tomography-depicted Gynecomastia in Spinal and Bulbar Muscular Atrophy

Rationale and Objectives: To evaluate the prevalence, size, and characteristics of gynecomastia on thoracic computed tomography (CT) in patients with spinal and bulbar muscular atrophy (SBMA) or amyotrophic lateral sclerosis (ALS), compared to those of patients with myasthenia gravis (as controls).Materials and Methods: A total of 189 male patients (SBMA [n = 15]; ALS [n = 76]; control [n = 98]) who underwent thoracic computed tomography were included. The size of breast glandular tissue diameters, and characteristic of CT-depicted gynecomastia were com-pared.Results: On multivariate logistic regression analysis, mean breast glandular tissue diameter (adjusted odds ratio [aOR] 1.13, 95% confi-dence interval [CI] 1.08-1.19), maximum breast glandular tissue diameter (aOR 1.14, 95% CI 1.08-1.20), prevalence of CT-depicted gynecomastia (aOR 21.71, 95% CI 5.39-87.38), dendritic or diffuse pattern of gynecomastia (aOR 35.30, 95% CI 8.02-155.40), and bilat-eral gynecomastia (aOR 41.96, 95% CI 10.20-172.69) were positively associated with SBMA, but not ALS. On receiver operating charac-teristic (ROC) analysis, the area under the curve of the mean breast tissue diameter for predicting SBMA was 0.92 with the optimal cutoff value of 16.5 mm. The ROC analysis showed that a maximum breast tissue diameter of 18.6 mm can also effectively distinguish SBMA from controls.Conclusion: These findings suggest that the evaluation of breast glandular tissue on thoracic CT could be a screening examination to dis-tinguish SBMA patients and assist in its differential diagnosis.