Publication:

WhyGM! – a prospective case-control study evaluating the etiology of idiopathic granulomatous mastitis

Background Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory condition affecting mostly young women usually within 5 years of childbirth and lactation. The etio-pathogenesis of this disease is not well understood leading to mismanagement causing progressive inflammation and multiple recurrences.

Methods It was a case-control study design with cases comprising patients with histopathological diagnosis of IGM and matched controls comprising women with benign breast disease other than IGM. All patients were interviewed with a structured questionnaire to determine potential risk factors. Serum sample was analysed for anti-nuclear antibody (ANA), prolactin, globulin and tissue from biopsy specimen was analysed in cases for microbial growth. Specific Autoantibody, Immunoglobulin assay was done in case of ANA positivity or elevated globulin levels

Results There was a significantly longer period of lactation (p=0.0002) and previous history of nipple discharge (p=0.038) among the cases. There was no evidence of uncommon infections caused by bacteria, mycobacteria or fungi. Markers for systemic autoimmunity such as serum ANA, Immunoglobulin levels (p=0.9531) and prolactin levels (p=0.1086) did not show a significant increase in case

Conclusions IGM was associated with a significantly longer period of lactation and nipple discharge. There was no significant correlation with systemic autoimmunity, hyperprolactinemia or infections. The aetiology of IGM remains elusive with potential for further research into localized autoimmune phenomenon.