Superficial ulcerating rheumatoid necrobiosis: a perforating rheumatoid nodule.

We report a case of superficial ulcerating rheumatoid necrobiosis (SURN), which is a recently described cutaneous manifestation of severe rheumatoid arthritis. As with classic rheumatoid nodule, there is evidence that this lesion may result from a vasculitis. SURN appears to represent a form of "perforating" rheumatoid nodule, and completes a triad of major necrobiotic processes (granuloma annulare, necrobiosis lipoidica, rheumatoid nodule) that have been reported to show epidermal perforation.