Abundance of plasma cells in a case of lipodermatosclerosis.

Plasma cells have been considered as an important morphological clue in the diagnosis of some sclerosing cutaneous diseases such as morphea, so much so that humoral immunology has been suggested to have a role in the pathogenesis of such diseases. Nevertheless, they are hardly ever described as a prominent feature in lipodermatosclerosis in which granulocytes have been claimed as the main pathogenic cell. We report a case of lipodermatosclerosis in a 77-year-old woman, in which plasma cells were abundant in the thickened fibrous septa of the hypodermis. They were highlighted on immunohistochemical study with CD79a, CD138 and EMA, and showed polyclonal immunoexpression of kappa and lambda immunoglobulin light chains.