MICHAEL E.MINGMD, MSCE
CARRIE ANN R.CUSACKMDSENAIT W.DYSONMDJACQUELINE M.JUNKINS-HOPKINSMD
Findings from microscopic examination demonstrated amorphous, eosinophilic material in the dermal papillae and reticular dermis, including around the blood vessels and appendages. The material was stained with periodic acid–Schiff. Laminin, type IV collagen, and CD34 expression were noted in the perivascular deposits, and anti-IgM labeled the amorphous substance. Electron microscopy revealed capillaries surrounded by electron-dense, finely granular material consistent with immunoglobulin deposits. Microscopic findings were consistent with IgM storage papules. His serum viscosity ratio was 2.1 (reference range, 1.4-1.8).
LIU V. Erythematous Papules on the Legs—Diagnosis. Arch Dermatol. 2009;145(1):77-82. doi:10.1001/archdermatol.2008.556-b