Granulomatous(lobular) mastitis is a distinct disease entity of unknown etiology which is characterized by noncaseating granulomatous lobulocentric inflammation. We describe a rare case of granulomatous(lobular) mastitis of a 36 year-old pregnant woman a review of the literature. The mass which was discovered in the third month of her pregnancy, began as a localized, nontender mass on the left breast and persisted during her entire pregnancy. It decreased slightly in size when she began taking post-partum bromocriptine. Clinically and mammographically, the mass was highly suspected as a carcinoma with axillary lymph node metastasis. Fine needle aspiration smears revealed numerous aggregates of granulomas composed of epithelioid histiocytes admixed with multinucleated giant cells of Langhans' and foreign body type, and collections of polymorphonuclear leukocytes.
Ziehl-Neelsen, silver methenamine and PAS stain were negative for acid-fast bacilli, fungus, and bacilli on the smear respectively. Histologically, granulomatous inflammation was centered on the breast lobules. Caseation necrosis was absent, instead, numerous microabscesses were formed in the center of the granulomas. Cultures of the fresh tissue for the AFB, aerobic and anaerobic bacteria, and fungus were all negative. Excision of the mass was performed without further treatment and there was no recurrence of the mass 6 months postoperatively. An autoimmune mechanism, infection, and some association with oral contraceptives have been suggested as etiologic factors in the literature.
Granulomatous mastitis is a rare inflammatory breast lesion, usually presented with rapidly enlarging palpable mass in young parous women and can simulate carcinoma. Unnecessary surgical procedure can be avoided if the nature of the lesion were defined by fine needle aspiratio(FNA) cytology.
We experienced a case of bilateral granulomatous mastitis diagnosed by FNA cytology. The patients was a 31-year-old woman with one month history of a rapidly enlarging mass in the left breast. considered clinically to be malignant.
After 4 years. she presented with a palpable mass in the right breast. The FNA cytology smears contained numerous aggregates of epithelioid histiocytes admixed with Langhans' and foreign body giant cells, lymphoytes, neutrophils and apoptotic debris leading to a diagnosis of granulomatous mastitis. The subsequent lumpectomy of the left breast confirmed the diagnosis of granulomatous mastitis. The FNA cytology smears from right breast showed identical cytologic findings.