Erythema nodosum‐like lesions in Behçet's syndrome: a histopathologic study of 30 cases

Abstract

Thirty patients who fulfilled the criteria for complete and incomplete types of Behçet's syndrome were studied to determine the histopathologic changes of erythema nodosum-like lesions. Lymphocytic vasculitis was observed in 12 (40%) of the cases, but it was only focal in areas of severe lymphocytic inflammation and only mild in degree. No diffuse vasculitis was seen. It is our opinion that the observed lymphocytic vasculitis is only secondary to moderate or severe lymphocytic inflammation. Twelve cases (40%) revealed septal panniculitis, 10 cases (33%) demonstrated lobular panniculitis with moderate to marked inflammation and fat cell necrosis, and 8 cases (27%) showed mild and nonspecific inflammation in the panniculus. Therefore, there is a spectrum of histopathologic changes of erythema nodosum-like lesions in Behçet's syndrome, similar to that of erythema nodosum secondary to other systemic disorders.

Adhesion molecule expression in erythema nodosum-like lesions in Behçet's disease

“…All patients and controls showed some focal vasculitic changes at areas of intense inflammation, which we accepted as sedondary reactive phenomena. Panniculitis was the prominent feature in both groups, as also re-55 ported by Chun et al [21]. We did not observe the acute necrotizing panniculitis with neutrophil infiltration that was reported in one patient in Chun's study [21].…”

“…However, they observed vasculitis only locally in the areas with moderate or severe inflammation, which they have accepted as a phenomenon secondary to the intense inflammation [27]. In another study, this group has found mild lymphocytic vasculitis in 12 of 30 (40%) cases with EN, which was only focal in areas of severe lymphocytic inflammation, which again was accepted as secondary to moderate or severe lymphocytic inflammation ("spilled-over phenomenon") rather than primary vasculitis [21]. No leucocytoclastic vasculitis was observed in EN lesions of these 30 patients with BD.…”

“…All of the diagnostic criteria sets currently in use for the diagnosis of BD have included oral ulcerations, genital ulcerations and skin lesions such as EN, pathergy phenomenon, pustules, folliculitis/acnelike lesions, ulcerations or subcutaneous thrombophlebitis either as major criteria or as items of diagnostic criteria as in the International Study Group Criteria [23,34]. Despite their high frequency and diagnostic importance, the exact nature of the histopathological features of mucocutaneous lesions in BD remains somehow controversial [21,[24][25][26][27][28][29][30][31][32][33]35]. The majority of the investigators have reported on mainly perivascular mononuclear cell infiltration in the mucocutaneous lesions of BD [21,[28][29][30][31][32][33] whereas some disagree and suggest a neutrophilic vascular reaction as the main histopathological lesion [24][25][26][27].…”

“…There have been several somewhat controversial reports on the histopathological findings of EN lesions in BD, which are usually called as "EN-like lesions of BD." In this regard some authors have emphasized primary vasculitis with neutrophilic infiltration [24][25][26][27], whereas others have reported focal and mild lymphocytic vasculitis mainly in areas of severe lymphocytic inflammation, which they suggested was secondary to severe inflammatory reaction [21,[28][29][30][31][32][33]. Some have observed abscess formation, some have described granuloma, and others have not observed these manifestations [21].…”

“…Its association with sarcoidosis, inflammatory bowel disease and Behçet's disease is well known. Erythema nodosum ocurs in about one-third of patients with BD [21,22]. The 1990 International Study Group Criteria for the Diagnosis of BD accepts erythema nodosum as one of its diagnostic manifestations [23].…”