[Detection of papilloma virus in Heck's focal epithelial hyperplasia and the differential diagnosis of white-sponge nevus].

Clinical, histological, and electron microscopical findings helped in to differentiating hyperplasia of a Turkish boy's oral mucosa as Heck's disease, and the hyperplasia of a young German man's oral mucosa as white sponge nevus. Electron microscopic investigations confirmed the presence of papillomavirus in the lesions of FEH.