Nephrogenic systemic fibrosis with septal panniculitis mimicking erythema nodosum.

Nephrogenic systemic fibrosis/nephrogenic fibrosing dermopathy is an idiopathic fibrosing disorder recently described in patients with renal disease. The typical histology in nephrogenic systemic fibrosis consists of haphazardly arranged dermal collagen bundles with clefting, collagenous change which extends into the subcutaneous septa, mucin deposition, fibroblast proliferation, and increased elastic fibers with minimal inflammation. We present a 65-year-old female with classic clinical features whose biopsy demonstrated unique histologic features of septal pannicilitis with lymphocytic aggregates and Miescher's radial granulomas mimicking erythema nodosum.