Breastfeeding and secretory factors in idiopathic granulomatous mastitis: Unveiling etiological insights

Idiopathic granulomatous mastitis (IGM) is a rare, chronic inflammatory, and benign breast disease. Its unclear etiology may involve autoimmune reactions, secretion-related factors, and microorganisms.

To analyze data from our IGM patient series and compare potential etiological factors.

We prospectively collected data using follow-up forms for patients diagnosed with IGM at our breast clinic from September 2014 to December 2020 and analyzed it retrospectively.

The study cohort included 220 patients, with a median age of 34 years (range: 20-58). A majority, 217 patients (98.6%), reported a history of breastfeeding, with a median duration of 36 months (range: 0-156). The median interval between the last breastfeeding session and disease onset was 25 (25th-75th percentiles: 15-44) months. Additionally, 116 patients (53.5%) reported breastfeeding-related problems. In 41 surgical patients, dense milky-brown debris in the breast ducts was noted. Although no independent seasonal fluctuations in disease onset were detected, a reduction in IGM cases during the summer months was found to correlate with a general decrease in all breast clinic visits.

Most patients reported recent breastfeeding and half experienced related problems, supporting the secretion theory's relevance in IGM's etiology. The absence of seasonal fluctuations suggests that secretion-related factors may be more central to IGM development than autoimmunity or infections. These findings offer crucial insights for future research into IGM's complex causes.