A 34 year old non-lactating female presented with complaints of intermittent fever, right breast pain and swelling for 25 days. There was no history of tuberculosis or breast carcinoma in the family members. She was initially treated with antimicrobials (flucloxacillin) in another health care center but her symptoms were not relieved.
On examination, there was a firm lump of 2 x 2 cm at the lateral margin of the areola of the right breast. It was slightly tender and overlying skin was red without any discharge. On ultrasonography, there was a cystic lesion in the right breast at 9 o'clock position measuring 4 x 5 mm. Surrounding the lesion was echogenic and edematous breast tissue likely to be focal mastitis. Ultrasound-guided FNAC of right breast lump was done. It showed moderately cellular benign ductal epithelial cells arranged in clusters and sheets, as well as in staghorn pattern intermingled by myoepithelial cells. Ill-defined granulomas along with multinucleated giant cells were also observed against a background of numerous neutrophils and epithelioid histiocytes (Fig. 1, Fig. 2, Fig. 3). Acid fast bacilli (AFB) stain of the specimen showed numerous AFB in clusters (Fig. 3).
The pathological diagnosis was given as Granumolatous mastitis, probably tuberculosis (Fig. 4). Polymerase Chain Reaction (PCR), Mantoux test and interferon gamma release (IGR) assay for Mycobacterium tuberculosis were advised to rule out other mycobacterial infection. Mycobacterium tuberculosis was detected on PCR and IGR assay (QuantiFERON-TB Gold test). She was then started with anti-tubercular treatment according to national protocol. Four drugs including rifampin, isoniazid, pyrazinamide and ethambutol were prescribed for four months which was followed by rifampicin and isoniazid for two more months. She was also prescribed with Vitamin B6 along with this tuberculosis drug regimen. Her symptoms resolved after six months of treatment.