White Sponge Nevus: Clinical Case and Narrative Review of the Literature

OBJECTIVES The aim of this article is to provide an epidemiological, diagnostic, and therapeutic overview of the white sponge nevus, through a narrative review of the literature and the presentation of a clinical case. MATERIALS AND METHODS The narrative review was conducted on PubMed, Google Scholar and Scopus, using the keywords "white sponge nevus", "white sponge nevus treatment" and "white sponge nevus differential diagnosis". Case reports and narrative reviews were included. In this article it is also described the case of a 19 years old patient who was referred by his dentist to our Oral Medicine department (S.C. Odontostomatology II, San Paolo Hospital, Milan) for white, diffuse, thicken and wrinkled plaque lesions, visible on the left and right buccal mucosa, and on the ventral surface of the tongue. RESULTS White sponge nevus is an autosomal dominant genodermatosis caused by mutations in the genes encoding for cytokeratin 4 and cytokeratin 13. It is a benign condition that affects 1 in 200.000 individuals without any racial and/or gender predilection. The onset of white sponge nevus is usually in infancy, childhood or adolescence, but the disease reaches its peak in early adulthood. From a clinical point of view, it is characterized by white-greyish, diffuse, soft, thicken and wrinkled plaque lesions. The most involved sites include the buccal mucosa bilaterally, the lips, the ventral surface of the tongue, the floor of the mouth, the soft palate and the alveolar mucosa. When the patients affected are young and free from risk factors, the medical history and the clinical features of the lesions are often enough to formulate a correct diagnosis. On the other hand, the incisional biopsy is fundamental in the mild or sporadic cases, or even in those patients for which it is important to rule out other conditions, such as the potential malignant disorders, that require different therapies or follow-up protocols. In the clinical case presented above, taking into account the positive familial history for the condition, the lesions appearance and the lack of symptoms, a clinical diagnosis of white sponge nevus was made. The patient did not undergo incisional biopsy, but periodical clinical examinations have been scheduled in order to evaluate any possible variation in the presentation of the lesions. CONCLUSIONS White sponge nevus is a benign and asymptomatic condition with no potential for malignant transformation. For these reasons it generally does not require any medical or surgical treatment. In most cases, patients may report only mild symptoms as a result of the altered texture of the oral mucosa. Nevertheless, if the lesions are wide or cause a sensation of discomfort to the patient, it is possible to opt for a surgical excision/reduction or laser-ablation of the plaques. CLINICAL SIGNIFICANCE The role of the dentist appears to be crucial in carrying out a correct differential diagnosis between white sponge nevus and epithelial lesions of another nature, from benign ones (such as pseudomembranous candidiasis, morsicatio buccarum, leukoedema.) to those belonging to the group of oral potentially malignant disorders (for example, leukoplakia, oral lichen planus, graft versus host disease-GVHD ... ).