Congenital ichthyosis patient with squamous cell carcinoma of the skin who received concurrent chemoradiation: A case report

Ichthyosis is a heterogeneous cluster of keratinization disorders. Autosomal dominant ichthyosis vulgaris, the most common type, has an estimated incidence of 1 in 250 births, and X-linked recessive ichthyosis, the second most common form, has an incidence of 1 in 6000 male births. In addition, there are approximately 6.7 in 100,000 cases of moderate-to-severe ichthyosis. Congenital ichthyoses are caused by mutations in the genes responsible for keratinocyte differentiation and skin barrier function. To date, there are 36 known forms of inherited ichthyoses, with over 25 genes being implicated and multiple mutations for each gene. In ichthyosis vulgaris, mutation of the filaggrin gene leads to a paucity or absence of the granular layer of the epidermis. This results in abnormal epidermal hyperplasia with excessive formation of stratum corneum, accompanied by abnormal desquamation. The main clinical feature of this disease is dry and rough skin with marked scaling but without inflammation. The skin of the abdomen and extensor surfaces is the most commonly affected, but the skin of the face and flexor surfaces is often spared. There is limited data on how patients with ichthyosis tolerate radiation therapy. Here we describe a case of a patient with congenital ichthyosis who underwent a course of radiation therapy concurrently with chemotherapy for treatment of squamous cell cancer of the skin.