Cobblestone appearance of oral mucosa: A diagnostic conundrum.

A 15-year-old boy presented with pink proliferative plaque over both lips. The child was born to a non-consanguineous couple, at full term, and uneventful antenatal, perinatal history. Examination revealed a cobblestone appearance over tongue with papilliferous projections in both labial mucosa with slate-grey pigmentation. The child had multiple lipomatosis and thyroid swelling. Father had thyroid swelling with multiple epidermoid cysts. A final diagnosis of Cowden syndrome. Genetic analysis could not be performed due to financial constraints. Oral mucosal cobblestone appearance is seen in Darier disease, Cowden's syndrome, lipoid proteinosis, granulomatous cheilitis, mucosal neuroma, Crohn's disease, and mucous membrane plasmacytosis. Diffuse oral mucosal melanosis is described in Peutz-Jeghers syndrome, Laugier-Hunziker-Baran syndrome, Cowden syndrome, and Addison's disease. We report this rare genodermatosis, which presents as oral papillomatosis. Early recognition of Cowden syndrome is crucial, as timely diagnosis enables appropriate cancer surveillance, genetic counseling, and preventive interventions, thereby reducing morbidity and improving long-term outcomes.