Clear cell acanthoma
{{Infobox medical condition (new)
| name =
| synonym =
| image = SkinTumors-P5280038.JPG
| image_size =
| alt =
| caption = Clear cell acanthoma (Degos)
| pronounce =
| specialty =
| symptoms =
| complications =
| onset =
| duration =
| types =
| causes =
| risks =
| diagnosis =
| differential =
| prevention =
| treatment =
| medication =
| prognosis =
| frequency =
| deaths =
}}
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; in dermoscopy this looks like "a string of pearls".{{cite journal| author=Tiodorovic-Zivkovic, D|author2=Lallas A|author3= Longo, C|author4= Moscarella, E|author5= Zalaudek, I|author6= Argenziano, G|title= Dermoscopy of clear cell acanthoma|journal= J Am Acad Dermatol.|year= 2015| volume=72| issue= 1 Suppl|pages =S47-9|doi= 10.1016/j.jaad.2014.06.039|pmid= 25500041}} 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.
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.
{{cite book |author=Odom, Richard B. |author2=Davidsohn, Israel |author3=James, William D. |author4=Henry, John Bernard |author5=Berger, Timothy G. |author6=Clinical diagnosis by laboratory methods |author7=Dirk M. Elston |title=Andrews' diseases of the skin: clinical dermatology |publisher=Saunders Elsevier |year=2006 |isbn=0-7216-2921-0 }}{{rp|636}}Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. {{ISBN|0-07-138076-0}}.{{rp|777}}