Fine needle aspiration cytology of granulomatous mastitis with special emphasis on microbiologic correlation

To describe the cytomorphology of granulomatous mastitis (GM) and to evaluate the causative agents involved, proven on the basis of microbiologic culture results and polymerase chain reaction (PCR) studies.

We retrospectively reviewed the inflammatory breast aspirates reported at King Abdul Aziz Specialist Hospital and Al Hada Armed Forces Hospital, Taif, Kingdom of Saudi Arabia, from January 2000 until March 2008. The pathology reports, clinical information, slides, microbiologic culture results and tuberculosis (TB)/PCR were reviewed. Cases of inflammatory carcinoma or duct ectasia were excluded.

A total of 49 cases of inflammatory breast aspirates were identified, of which 15 cases were GM. The microbiologic cultures of all 15 cases were available. Six of 15 cases had positive culture for Brucella melitenses, and 2 cases were positive for TB, which was further confirmed by TB/PCR. The fungal cultures were negative in all the cases. Seven of 15 cases were classified as idiopathic GM.

Fine needle aspiration cytology was found to be a useful tool in the early diagnosis of GM and its classification if performed by a pathologist as the material can be submitted for culture. The definitive diagnosis can be established by a combination of the cytomorphologic features and microbiologic studies.