Idiopathic granulomatous mastitis with extramammary manifestations: a case report

Granulomatous mastitis is a rare inflammatory disorder of the breast, which can be either idiopathic or due to secondary etiology. This disease affects women of reproductive age. The exact pathophysiology underlying idiopathic granulomatous mastitis (IGM) remains unclear, but it is believed to be mediated by immunological processes. Establishing a diagnosis of this condition could be challenging due to the long list of differential diagnoses that it creates. We report a 24-year-old Syrian female presented to the clinic complaining of a 2-week history of fatigue, fever and chills, swelling, and localized pain in her left breast. Physical examination revealed erythema nodosum, episcleritis, and arthralgia in the wrists, ankles, and elbows. An excisional biopsy was done and a microscopic examination of the lesion confirmed granulomatous perilobular mastitis. Symptoms had resolved after the surgical excision and follow-up evaluation showed no signs of recurrence. IGM typically presents as an enlarging breast mass that can be mistaken for breast cancer or an abscess. The diagnostic approach should consider the presence of extramammary symptoms such as fever, arthralgia, and fatigue. Treatment options include corticosteroids, surgical excision, or steroid-sparing agents, but relapse rates vary. Episcleritis should be considered as a potential extramammary manifestation in cases of IGM. We highlight the importance of recognizing and investigating the potential systemic involvement in patients with IGM. Accurate interpretation of pathological and radiological findings by a multidisciplinary breast team can facilitate the diagnosis and reduce unnecessary interventions.