CD34-Reactive Myxoid Dermal DendrocytomaOhata, Chika M.D.; Kawahara, Kunimitsu M.D., Ph.D.American Journal of Dermatopathology: February 2002 - Volume 24 - Issue 1 - pp 50-53 Extraordinary Case Reports Abstract Author Information Normal skin is composed in part of cells that express CD34. These include periadnexal spindle cells, vascular endothelial cells, and interstitial dendritic cells. We report on a tumor composed mainly of CD34-reactive spindle cells. A 66-year-old Japanese woman presented with a skin-colored, dome-shaped, cutaneous papule on her left palm that was 7 mm in diameter and had developed within the preceding 3 months. Light microscopic examination showed a well-circumscribed polypoid tumor consisting of spindle-shaped cells and thin collagen fibers arranged loosely in a fascicular pattern within a myxoid matrix. Immunohistochemically, most of the tumor cells stained strongly for CD34, but did not stain with antibodies to S-100 protein, smooth muscle actin, desmin, neuron-specific enolase, epithelial membrane antigen, or factor XIIIa. Staining for vimentin and CD68 was positive. We believe this lesion to be a CD34-reactive myxoid dermal dendrocytoma of a type that has not been described previously. From the Department of Dermatology, Toyonaka Municipal Hospital (C.O.) and Department of Pathology, Osaka National Hospital (K.K.), Osaka, Japan. Address correspondence and reprint requests to Chika Ohata, M.D., Department of Dermatology, Toyonaka Municipal Hospital, 4-14-1, Shibahara, Toyonaka, Osaka, 560-8565 Japan; E-mail: firstname.lastname@example.org. © 2002 Lippincott Williams & Wilkins, Inc.