A Rare Case of Sarcoidosis Presenting as an Isolated Breast Mass and Pain: A Case Report and Literature Review.

BACKGROUND Sarcoidosis is a benign systemic granulomatous disorder of unknown etiology that affects multiple organs. Patients diagnosed with sarcoidosis usually present with nonspecific symptoms: fatigue, fever, weight loss, and respiratory symptoms such as cough and dyspnea; 50% of the patients are asymptomatic at the time of diagnosis. In 90% of patients, sarcoidosis targets hilar and mediastinal lymph nodes. In rare cases, it presents solely in the breast with no other symptoms. The diagnosis is established based on compatible clinical and radiological findings and supported by histological evidence in 1 or more organs of non-caseating epithelioid cell granulomas in the absence of organisms or particles. CASE REPORT We herein present a unique case of a 27-year-old woman who presented with pain and swelling in her left breast. On examination, the left breast revealed multiple, firm-hard, and tender masses. Breast ultrasound showed large loculated focally dilated ducts with significant periductal vascularity and inflammation. Fine-needle aspiration (FNA) showed an inflammatory process with granulomatous formation. An ultrasound-guided core biopsy, which was histologically consistent with granulomatous mastitis, and elevated angiotensin-converting enzyme (ACE) levels confirmed a diagnosis of sarcoidosis. The patient was started on IV steroids followed by oral prednisolone and azathioprine. During treatment, the mass size decreased and the pain substantially improved. CONCLUSIONS It is important to consider sarcoidosis in a patient who presents with only pain and swelling in the breast to ensure early diagnosis and initiate treatment, improving the patient's overall prognosis.