The frequency of co-occurrence of Hashimoto disease in granulomatous mastitis patients and its relation to...

Idiopathic granulomatous mastitis (IGM) is a benign, chronic inflammatory breast disease frequently associated with autoimmune disorders. This prospective cohort study explored the prevalence of Hashimoto thyroiditis (HT) in patients with IGM and the relationship between this co-occurrence and systemic inflammatory markers.

Between March 2019 and September 2022, 179 women were enrolled: IGM without HT (n = 52), IGM + HT (n = 19), and age-matched healthy controls (n = 89). Hematological indices, including white blood cell count, C-reactive protein, neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR), were measured at diagnosis before any treatment.

The prevalence of HT among patients with IGM was 26.8 %. Compared with isolated IGM, the IGM + HT group had a lower smoking rate (16.3% vs 40.4%, P = .028) and displayed a significantly lower median NLR (1.91 vs 2.76, P < .001) but higher median LMR (6.47 vs 4.75, P = .001).

Approximately 1 in 4 women with IGM also had HT. A low NLR-high LMR pattern may reflect a distinct inflammatory milieu in this overlap cohort and could help tailor follow-up strategies for these patients. Routine thyroid screening should be considered in patients with IGM.