Familial Melanoma Phenotype With Xeroderma Pigmentosum Group C (XP-C) Genotype - The Putative Role of MC1R Polymorphism as Modifier.

Introduction: Xeroderma pigmentosum (XP), a rare inherited condition, hallmarked by extreme sensitivity to sun exposure resulting in multiple skin cancers and non-malignant skin alterations is attributed to homozygous inactivating pathogenic variants (PVs) in DNA repair genes, predominantly the XPC gene.

Objectives: Report a unique phenotypic expression of mutant XPC allele that may be compatible with a putative modifier role for MC1R polymorphism.

Methods: A family of 13 siblings, seven of whom were diagnosed with at least one cutaneous melanoma (N = 53) and non-melanoma skin cancers (N = 9) was studied.

Case for diagnosis. Metastatic Crohn's disease.

Metastatic Crohn's disease is a rare skin manifestation, defined by granulomatous skin lesions that are discontinuous to the affected gastrointestinal tract and histopathologically resembling inflammatory bowel lesions. Up to 44% of patients with Crohn's disease have cutaneous manifestations, of which metastatic lesions are the least common. We present a case of an adolescent with refractory Crohn's disease and persistent papules and plaques on the skin.