A variant of nephrogenic fibrosing dermopathy with osteoclast-like giant cells: a syndrome of dysregulated matrix remodeling?

Nephrogenic fibrosing dermopathy (NFD) is a disorder characterized by dramatic thickening and hardening of skin in the extremities and trunk, which occurs in individuals on dialysis for renal disease. The pathophysiology is unknown. Increased transforming growth factor-beta (TGF-beta) and collagen deposition have been reported in a small group of patients studied by Jimenez et al.1 We report two patients with NFD and osteoclast-like giant cells in the fibrotic dermis; one patient also had dystrophic cutaneous calcification. These findings have been seen in a small percentage of NFD patients (estimated 2-5%) and may represent a variant of the disease. The hypothesis of altered matrix dysregulation due to altered TGF-beta, metalloproteinases, and activation of osteoclasts as an explanation for this variant is proposed.