Massive cutaneous mucinosis associated with systemic lupus erythematosus.

We describe a 23-year-old Japanese man with systemic lupus erythematosus (SLE) who developed massive cutaneous mucinosis. He was diagnosed with SLE when he was 11 years old. Prednisolone therapy (30 mg/day) was initiated and reduced to 10 mg/day 3 months later; the SLE had been well-controlled with this dose of prednisolone for 12 years. However, infiltrated erythematous plaques developed on the middle-lateral area of his back at 17 years old and progressed to erythematous and elastic soft tumorous masses over 20 cm in diameter at 23 years old. Biopsies of the lesions on the nape revealed massive mucin deposition. Topical injection with hyaluronidase decreased the lesion. This cutaneous mucinosis can be distinguished clinically and histopathologically from papular and nodular mucinosis associated with SLE. The present case might be an unusual clinical variant of cutaneous mucinosis associated with SLE.