SUMMARY The clinical and pathological features of nine cases of granulomatous mastitis were compared with those of 10 cases of duct ectasia/periductal mastitis (DE/PM), all of which were associated with active granulomatous inflammation. Granulomatous mastitis affects a younger age group, and although there is some overlap with DE/PM, it has distinctive pathological features, particularly a lobule centred distribution, for which the term "granulomatous lobular mastitis" is recommended. There is a strong tendency for persistence or recurrence. Our cases of granulomatous mastitis all occurred in parous women, five of them within three years of pregnancy.Awareness of this condition is important, because surgery does not offer the best treatment of recurrent disease, and trials of adequate drug treatment, including corticosteroids, are required.Granulomatous mastitis was first clearly described as a separate entity in 1972 by Kessler and Wolloch,' who reported five women, in whom breast masses were. due to a florid, sometimes necrotising, granulomatous lobulitis that was not associated with trauma, specific infection, or exogenous material. Since then, the largest published series has been that of Fletcher et al2 ( The pathogenesis of granulomatous mastitis is unclear, as is its relation to the duct ectasia/periductal mastitis (DE/PM) group of conditions, in which a granulomatous inflammatory component may be present. This study aimed to examine the clinical and pathological association between granulomatous mastitis and the granulomatous variants of DE/PM.
Material and methodsWe reviewed nine cases of granulomatous mastitis biopsied in Edinburgh from 1975-86 and compared them with 10 cases of DE/PM in which there was prominent granulomatous inflammation. Some of the DE/PM group had been identified in connection with a separate study of mammary duct ectasia.'2 The Accepted for publication 9 December 1986 notes were obtained for all cases and the clinical data reviewed. The slides were obtained for all biopsy specimens, and where necessary, the blocks were recut and restained. Special stains (Gram, Ziehl-Neelsen, and Grocott's methenamine silver method) were examined for organisms. In four of the cases of granulomatous mastitis (cases 2, 4, 8 and 9) and one case of DE/PM (case 11) in which further biopsies were performed, fresh tissue was submitted for microbiological examination, including culture for Mycobacterium tuberculosis. In these and a further four cases wound swabs were also submitted. Special transport media were not used.
