Eosinophilic mastitis masquerading as breast carcinoma

We report the sixth case of Eosinophilic Mastitis, presenting similarly enough to be confused with breast carcinoma. A 50 year old lady presented with a six month history of progressively enlarging asymptomatic breast lump, cough and breathlessness. Clinical examination, mammography and axillary lymphadenopathy suggested malignant disease. Ronchi were heard on chest auscultation. Needle cytology was twice inconclusive and Tru-cut biopsy showed acute on chronic inflammation. Blood investigations revealed significant peripheral eosinophilia. Open biopsy reported eosinophilic mastits, correlating with peripheral eosinophilia and pulmonary symptoms. The patient responded to conservative management. Eosinophilic infiltration of the breast is a rare manifestation of tissue involvement in peripheral eosinophilia. Asthma, Churgh-Strauss Syndrome and hyper-eosinophilic syndromes are associated. Importantly, if a clinically and radiologically malignant breast lump in asthmatic ladies with peripheral eosinophilia is not confirmed on cytology, this entity could be a diagnosis, potentially saving the patient from surgery.