clear cell acanthoma clear cell acanthoma clear cell acanthoma (also known as acanthome cellules claires of degos and civatte, degos acanthoma, and pale cell acanthoma) is a benign clinical and histological lesion initially described as neoplastic, which some authors now regard as a reactive dermatosis. it usually presents as a moist solitary firm, brown-red, well-circumscribed, 5 mm to 2 cm nodule or plaque on the lower extremities of middle-aged to elderly individuals. the lesion has a crusted, scaly peripheral collarette and vascular puncta on the surface. it is characterized by slow growth, and may persist for years. the clinical differential diagnosis includes: dermatofibroma, inflamed seborrheic keratosis, pyogenic granuloma, basal-cell carcinoma, squamous cell carcinoma, verruca vulgaris, psoriatic plaque, and melanoma. clear cell acanthomaclear cell acanthoma (degos)specialtyoncology histology clear cell acanthoma is characterized by a sharply demarcated psoriasiform epidermal hyperplasia composed of a proliferation of slightly enlarged keratinocytes, and basal cells with pale-staining glycogen-rich cytoplasm, mild spongiosis and scattered neutrophils, which may form small intraepidermal microabscesses. oedematous dermal papillae are typically seen with increased vascularity and a mixed inflammatory infiltrate including lymphocytes, plasma cells and neutrophils. treatment simple surgical excision is curative. : 636 : 777