GRANULOMATOUS LOBULAR MASTITIS - A CLINICOPATHOLOGICAL STUDY OF 12 CASES

We report 12 cases of granulomatous lobular mastitis occurring in youn g women, between ages 30 and 47 years, diagnosed at King Faisal Specia list Hospital and Research Centre (KFSH&RC) from 1987 to 1995. The dis ease was unilateral in 10 cases, while there was a history of involvem ent of the contralateral breast in two patients. At the time of diagno sis, two patients were lactating, two were pregnant, and two were preg nant and lactating. Histopathological examination in all cases reveale d centrilobular granulomas and microabscess formation. Immunohistochem ical staining in seven cases for T and B cell markers showed a predomi nance of T cells in the infiltrate in all cases. The treatment compris ed surgical removal of the mass, debridement and antibiotics in some o f the cases. In one patient referred from another institution, mastect omy had been performed on the basis of an erroneous histopathologic di agnosis of carcinoma. Preoperative diagnosis was carcinoma in seven ca ses and benign disease in the remaining five cases. Follow-up of the p atients was uneventful in all cases. Granulomatous lobular mastitis is a rare inflammatory disease of the breast, which may clinically and p athologically mimic carcinoma, sometimes leading to misdiagnosis resul ting in unnecessary surgery.