Resident Rounds Part III: Scleromyxedema: A Rare Disorder Associated With a Monoclonal Gammopathy

A 72-year-old man originally from Grenada presented to the dermatology clinic at SUNY Downstate Medical Center for evaluation of a generalized rash. The patient reported a three year history of a progressive rash, with increased thickening of his skin, and pruritus. He also noted swelling of his hands and fingers with decreased range of motion and a left eyelid ptosis. He was treated by an outside dermatologist with topical triamcinolone and halobetasol for one year without improvement based on a biopsy report showing granuloma annulare. Review of systems was otherwise negative. His medical history was significant for hypertension and glaucoma. His additional medications included pantoprazole, amlodipine, travanoprost, atenolol, and aspirin.

Physical exam revealed numerous waxy, erythematous 2-3mm papules coalescing into thickened hyperpigmented plaques covering much of the neck, chest, back, and extremities. Indurated skin folds were most evident in the lateral trunk, axillae, and upper arms consistent with the "Shar-Pei sign". (Figure 1). In several areas, the papules formed linear arrays. His hands were sclerotic with swelling of all digits. The patient had a left eyelid ptosis, loss of eyebrow hair bilaterally (madarosis), and a leonine facies (Figure 2). Two 4 mm punch biopsies of the chest and back revealed a proliferation of plump fibroblasts interposed between slightly thickened collagen bundles with hints of mucin deposition (Figures 3a and 3b). Immunostains for Factor XIIIa and CD34 were positive while S-100 and CD1a were negative, consistent with a diagnosis of scleromyxedema (Figure 4). Serum and urine electrophoresis demonstrated an IgG-kappa monoclonal gammopathy. The patient was referred to hematology/oncology for further management.

Scleromyxedema is an idiopathic primary cutaneous mucinosis affecting middle-aged adults. It is characterized by dermal mucin deposition with increased collagen in the skin and internal organs. Patients present with waxy papules and plaques with sclerodermoid changes.¹ Patients typically have a monoclonal gammopathy and systemic manifestations. The significance of the monoclonal gammopathy is unclear and paraprotein levels do not always correlate with disease severity or clinical course.² Furthermore, most patients do not go on to develop multiple myeloma. Internal manifestations vary and can include muscular, neurologic, gastrointestinal, pulmonary and cardiovascular complications. The most common extracutaneous manifestation of scleromyxedema is dysphagia.³ Treatment is often unsuccessful and has included a range of agents such as melphalan, systemic steroids, phototherapy, intravenous immunoglobulins, plasmapheresis, electron beam radiation, and various chemotherapies. More recently, combinations of thalidomide and dexamethasone, lenalidomide, bortezomib, and autologous hematopoietic stem cell transplantation have been tried.^4-7 Spontaneous resolution has rarely been reported.²

Histopathology Photos by Qiang Xie MD.