Imaging manifestations of idiopathic granulomatous lobular mastitis on cone-beam breast computed tomography

To evaluate the imaging manifestations of idiopathic granulomatous mastitis (IGM) on cone-beam breast computed tomography (CBBCT).

We retrospectively evaluated the clinical data of 22 female patients (mean age, 34.73 ± 10.41 years; range 20-58 years) with IGM pathologically confirmed by biopsy or resection. The non-contrast-enhanced CBBCT features, contrast-enhanced CBBCT features, contrast enhancement rate, time-density curve (TDC) and Breast Imaging-Reporting and Data System category of IGM were assessed. The contrast enhancement rates of IGM lesions at 60 s, 120 s and 180 s after injection of contrast agent were compared using ANOVA.

All 22 patients with IGM showed non-mass enhancement on CBBCT. Approximately 40.9% (9/22) of IGM lesions displayed diffuse patchy or focal nodular enhancement on CBBCT, 31.8% (7/22) showed mammary duct dilation, 13.6% (3/22) showed pseudocystic appearance, and 13.6% (3/22) manifested as honeycomb cysts. Among the 22 patients, 72.7% (16/22) displayed type I TDC (persistently enhancing pattern) and 27.3% showed type II TDC (plateau pattern) on contrast-enhanced CBBCT.

IGM mainly manifests as non-mass enhancement on CBBCT, with persistently enhancing or plateau TDC. CBBCT efficiently displays detailed features of IGM with high-density resolution and hemodynamic characteristics.