RESUMO
OBJECTIVE: White sponge nevus (WSN) is a rare autosomal dominant disorder that results in soft, white, and spongy plaques in the oral mucosa. The aim of this study was to describe the clinical, histopathologic, and genetic features of a family, spanning 3 generations, affected by WSN. STUDY DESIGN: This study was performed using a cross-sectional layout analyzing a family with WSN. RESULTS: Clinical examination of family members revealed that of 23 descendants, 8 (34.78%) had WSN features. Unaffected and affected members transmitted the disease to their offspring. The offspring recurrence risk was 0.34, and an incomplete level of penetrance was observed. The lesions showed many clinical and histopathologic similarities to cases previously reported. The most affected sites were buccal and labial mucosa, with a rare appearance in the palate. No extraoral lesion was found. Histological examination showed intense acanthosis and hyperparakeratosis-induced epithelial hyperplasia. Within the spinous layer, cells showing perinuclear eosinophilic condensation of the cytokeratin (CK) filaments were frequent. CONCLUSION: The disease was transmitted by an autosomal dominant mode of inheritance, appearing mainly in the buccal and labial mucosa.