Lupus erythematosus panniculitis.

Lupus erythematosus panniculitis is an uncommon variant of lupus erythematosus characterized by a specific involvement of the subcutaneous fat. It is a panniculitis with peculiar clinical features and histopathologically characterized by a mostly lobular panniculitis. It may appear in patients with discoid lupus erythematosus and systemic lupus erythematosus, but also as the unique manifestation of lupus erythematosus, and in the latter cases the diagnosis may be problematic. Histopathologic differential diagnosis with subcutaneous panniculitis-like T-cell lymphoma may also be extremely difficult. This article reviews the salient clinicopathologic features and treatment of lupus erythematosus panniculitis, with special emphasis on the histopathologic features.