dermatologic disorders
Basal Cell Carcinoma
Introduction
Basal cell carcinoma is a superficial, slowly growing papule or nodule that derives from certain epidermal cells. Basal cell carcinomas arise from keratinocytes near the basal layer, which are sometimes called basaloid keratinocytes. Metastasis is rare, but local growth can be highly destructive. Diagnosis is by biopsy. Treatment depends on the tumor’s characteristics and may involve curettage and electrodesiccation, surgical excision, cryosurgery, topical chemotherapy, or, occasionally, radiation therapy or medications. (See also Overview of Skin Cancer .) Basal cell carcinoma is the most common type of skin cancer, with approximately 2 million new cases yearly in the United States ( General reference ). It is most common among people with light skin with a history of sun exposure and is very rare in people with dark skin. Basal cell carcinomas are also associated with genetic syndromes and may arise in a nevus sebaceus (nevus sebaceous). Xeroderma pigmentosum represents an inherited defect in DNA repair that can result in nonmelanoma skin cancer and in Melanoma . Basal cell nevus syndrome (Gorlin syndrome) is an autosomal dominant disorder that results in multiple basal cell carcinomas as well as in medulloblastomas, meningiomas, breast cancers, non-Hodgkin lymphomas, and ovarian cancers. Bazex syndrome is a rare genodermatosis that can result in the early onset of multiple basal cell carcinomas. 