Sclerosing or Morpheaform Basal Cell Carcinoma
Morpheaform BCC is an insidious tumor possessing innocuous surface characteristics that can mask its potential for deep, wide extension. The tumor is waxy, firm, flat-to-slightly raised, either pale white or yellowish, and resembles localized scleroderma, thus the designation morpheaform. The borders are indistinct and blend with normal skin. Lesions may become depressed and firm, resembling a scar. The tissue is rigid and difficult or impossible to remove with a curette. Localization of this tumor by inspection or biopsy is impossible. The average subclinical extension beyond clinically delineated borders was 7.2 mm in one study. Treatment consists of wide excision or, preferably, Mohs’ micrographic surgery.