Nonsyndromic type of hereditary multiple basal cell carcinoma

An autosomal dominant phenotype characterized by multiple superficial basal cell carcinomas (BCC) without associated anomalies is postulated on the ground of the following data. There are several reports on multiple BCC occurring in two generations of a family, including male-to-male transmission. There are also three reports of a strictly unilateral manifestation of multiple superficial BCC, suggesting mosaicism. The father of one of the patients with unilateral involvement was affected with multiple disseminated BCC, which suggests a type 2 segmental manifestation in the son, reflecting loss of heterozygosity that occurred at an early stage of embryogenesis. The three cases of unilateral arrangement would be difficult to explain without the assumption that multiple nonsyndromic superficial BCC may occur as a distinct mendelian trait.