Trichoepithelioma papulosum multiplex

Trichoepithelioma papulosum multiplex is an uncommon autosomal dominant disorder in which multiple trichoepitheliomas are seen. Its cause may be a defective tumor suppressor gene. Studies have mapped this gene to the 9p21 locus. However, there is a parallel or identical syndrome of multiple trichoepitheliomas and cylindromas. Within a given family, some members may have cyclindromas whereas others may have trichoepitheliomas or a combination of both. Although preliminary evidence suggests a different gene is responsible, it is possible that TPM may be caused by more than two independent genes, with some cases of TPM due to impairment of the gene for cylindromatosis. This entity, as well as other disorders with multiple appendageal tumors, may require clarification and distinction from TPM.