18781 A familial case of white sponge nevus and review of the literature

Abstract

White sponge nevus (WSN) is an autosomal dominant skin disorder characterized by white corrugated and diffuse plaques mainly affecting the non-keratinised stratified squamous epithelium. Although WSN is usually seen in the oral mucosa, other sites, such as the nasal, esophageal, laryngeal, and anogenital mucosa, may also be involved. We describe a case a 11-year-old girl who presented with asymptomatic rough, diffuse, white patches in the bilateral buccal mucosa gingiva with extension to the esophagus that was evident on esophageal gastroduodenoscopy. A biopsy of esophageal tissue confirmed the presence of WSN. Her father had a similar biopsy-proven but more widespread appearance in the buccal mucosa and esophagus as well. WSN is caused by germline variants of the keratin genes KRT4 or KRT13, located, respectively, at chromosomes 12q13 and 17q21-q22. Extra-oral affected sites have been shown to arise only from KRT13 variants. It is important to recognize this benign entity and to differentiate it from other acquired causes of intra-oral white plaques such as leukoplakia, candidiasis and lichen planus. A thorough history and physical examination would help to exclude other genodermatoses like pachyonychia congenita, hereditary benign intraepithelial dyskeratosis, Darier disease, and dyskeratosis congenita.