Nevus spongiosus albus mucosae D10.31

Nevus spongiosus albus mucosae is a rare (harmless), autosomal-dominant inherited keratinization disorder affecting the non-keratinized, stratified squamous epithelium of the mucous membranes. The oral mucosa is mainly affected. More rarely, the anal and vaginal mucosa and the nasal mucosa are also affected to varying degrees.

Autosomal dominant inheritance; causative mutations are present in the KRT13 and KRT4 genes, which are mapped on chromosomes 17q21-q22 and 12p11.2-q11, respectively (nucleotide substitution from G to A in position 1345 of the KRT4 gene). To date, 6 mutations have been detected. The mutations lead to the formation of defective keratin proteins and consequent disruption of keratin filatments (Westin M et al. 2018).

Significant acanthosis, intra- and extracellular edema with vacuolisation of epithelial cells, parakeratosis, inflammatory infiltrate. Epidermolytic hyperkeratosis has also been described.

Cheap. The changes of the oral mucosa reach their maximum expression in the 2nd decade of life. After that they do not change any more.

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2. Cannon AB (1935) White sponge nevus of the mucosa (nevus spongiosus albus mucosae). Arch Dermatol Syph 31: 365
3. Chao SC et al (2003) A novel mutation in the keratin 4 gene causing white sponge nevus. Br J Dermatol 148: 1125-1128.
4. Mostaccioli S et al (1997) White sponge nevus is caused by mutations in mucosal keratins. Eur J Dermatol 7: 405-408
5. Schaarschmidt H et al (1992) Nevus spongiosus et albus mucosae. Dermatol 43: 35-37.

6. Westin M et al (2018) Mutations in the genes for keratin-4 and keratin-13 in Swedish patients with white sponge nevus. J Oral Pathol Med 47:152-157.