Xanthoma disseminatum

A 46‐year‐old woman presented to the Department of Dermatology with an 8‐year history of progressive asymptomatic papular and nodular lesions on the trunk. She denied ocular symptoms, hoarseness, difficulty with breathing, polydipsia, or polyuria. A histopathologic examination of the anterior cruciate ligaments following their rupture and reconstruction showed an extensive xanthomatous process. She was otherwise healthy. Physical examination revealed coalescing red–brown papules and nodules on the trunk, primarily the groin and axillae, bilaterally ( Fig. 1). The buccal mucosa was normal. The serum lipids revealed a normal level. Immunoelectrophoresis, hematologic, and biochemical screening were normal. An excisional biopsy was performed and the microscopic and ultrastructural findings are shown in Figs 2 and 3. Figure 1 Left axilla. Coalescing red–brown papules and nodules2The infiltrate in the dermis is characterized by scalloped and xanthomitized cells3Histiocyte with myeloid bodies (arrows), fatty droplets, vacuolic dense bodies dense bodies (V), and some rhomboid crystal structures (C) The entire dermis was heavily infiltrated with Touton giant cells and mononuclear cells representing all five histiocytic cell types (vacuolated, spindle‐shaped, xanthomitized, scalloped, and oncocytic). Apart from a few vacuolated and some spindle‐shaped and oncocytic cell types, the infiltrate was characterized by scalloped and xanthomitized cells. Oncocytic cells had a rather pronounced, eosinophilic, homogeneous, slightly granular cytoplasm with well‐demarcated cell borders. Furthermore, a demarcating lymphocytic infiltrate was seen ( Fig. 2). Ultrastructurally, the histiocytes showed myeloid bodies, fatty droplets, and dense bodies, together with some rhomboid crystal structures ( Fig. 3). These findings are consistent with xanthoma disseminatum.