Clinicopathologic evaluation of nodular cutaneous lesions of Behcet syndrome

Among the cutaneous manifestations, nodular lesions are rather common in Be hcet syndrome. The histologic nature of these lesions has been a matter of controversy. To establish their distinguishing features, biopsy specimens f rom nodular lesions of 24 patients with Behcet syndrome, 25 with nodular va sculitis (NV), and 20 with erythema nodosum (EN) were compared. Statistical analysis revealed insignificant differences between most of the histologic features of Behcet syndrome and NV However neutrophil-predominating infilt rate in the subcutis was more common in Behcet syndrome, while necrosis and granuloma formation were encountered more frequently in NV The differences between Behcet syndrome and EN were more significant. Septal panniculitis, lymphocyte-predominating infiltrate, absence of many vascular changes as w ell as vasculitis, and necrosis were features in favor of EN. Nodular lesio ns of Behcet syndrome are mainly neutrophilic vascular reactions with histo logic features similar to NV but significantly differing from EN associated with other systemic diseases.