Recessive dystrophic epidermolysis bullosa-associated squamous-cell carcinoma: an enigmatic entity with complex pathogenesis.

Expression of either collagen VII or the noncollagenous (NC1) fragment derived from it has been suggested to be indispensable for the development of squamous-cell carcinomas (SCCs) in patients affected by recessive dystrophic epidermolysis bullosa (RDEB). This view is challenged here by the observation that SCCs do develop in RDEB patients lacking expression of collagen VII altogether. The aggressive behavior of RDEB-associated SCCs remains unexplained.