EOSINOPHILS ARE NOT A CLUE TO THE PATHOGENESIS OF GRANULOMA-ANNULARE

Eosinophils are variably present in biopsy specimens of granuloma annu lare (GA). A retrospective study of 77 biopsy specimens from 73 patien ts with GA was performed to quantitate eosinophils and correlate the f indings with both histologic and clinical features. Specimens were div ided into absent, low (10 > x greater than or equal to 1 eosinophils p er 3 sections), and high (x greater than or equal to 10 eosinophils pe r 3 sections) eosinophil groups and evaluated for eight histologic and 11 clinical features. Eosinophils were identified in 66% (51/77) of b iopsy specimens, with 51.9% (40/77) and 14.3% (11/77) in the low and h igh eosinophil groups, respectively. Clinically, patients in the high eosinophil group were found to be significantly younger with a propens ity towards nonannular, localized disease. These patients also did not have diabetes or use systemic medications. Histologically, the presen ce of eosinophils was strongly associated with palisaded architectural pattern and the presence of necrobiosis. Eosinophils were not present in areas of necrobiosis but were found pre dominantly perivascularly. A moderate to marked lymphocytic infiltrate at the periphery of the g ranulomas and reactive vessel changes were common in all three groups, but vasculitis was not identified. In summary, this study showed eosi nophils to be commonly present in GA but was unable to correlate their presence with specific clinical or histologic features supportive of an allergic precipitant. A cell-mediated immune mechanism is likely in volved in GA, with eosinophils recruited nonspecifically by mediators released during granuloma formation.