Clinicopathological evaluation of idiopathic granulomatous mastitis patients: A retrospective analysis from a tertiary care hospital in Turkey.

Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory disease of the breast with unknown etiology that is characterized by granuloma formation. We analyzed the clinical, radiological, and therapeutic approaches; the recurrence rate of the disease; and the pathological findings diagnosed with mastitis in a retrospective study. We evaluated a total of 77 patients subjected to core needle or excisional biopsy with preliminary diagnosis of mastitis between January 2017-December 2019 who diagnosed with IGM, nonspecific mastitis/abscess, or periductal mastitis/plasma cell mastitis as a result of their pathological assessment. The mean age was 39.24 ± 10.6. Though 65 patients were diagnosed with IGM (84.4%), other diagnoses were reported as nonspecific mastitis/abscess (n = 9), periductal mastitis (n = 2) and plasma cell mastitis (n = 1). Recurrence occurred in 30 (39%) patients during follow-up. In patients without IGM, the number of 5-year postpartum mastitis diagnoses was significantly higher (p = 0.0008) while number of 2-year postpartum mastitis diagnoses was lower (p = 0.255) compared to those in IGM patients. The rates of axillary lymphadenopathy, bacterial culture, parity, and menopausal status were not different in patients without IGM. Linear correlation analysis did not reveal a significant relationship between radiological preliminary diagnosis and pathological diagnosis with BI-RADS classification. A detailed assessment, accompanied with clinical, radiological, and pathological findings, should be performed to achieve an accurate diagnosis and effective patient management in IGM. Furthermore, IGM should always be considered in the differential diagnosis of mastitis among breast masses.