Non-specific granulomatous mastitis (NSGM) is a tumor-like inflammatory condition involving breast lobules. Its recognition is of great significance because of clinical masquerade to invasive carcinoma. A 25-year-old woman developed a palpable breast lump with clinical and mammographic findings suggestive of malignancy. Touch imprint cytology of the excised lump was consistent with a granulomatous inflammation while histopathological examination documented a NSGM with central necrosis. Clinical, radiologic and laboratory testing failed to identify any specific causative agent.