Size, surface and consistency
Both papilloma and fibromas are less than 1 cm in size, have a smooth surface and are pedunculated, but papilloma might present with an irregular surface and fibroma with a covering of mucosal surface. Torus is a submucosal bony outgrowth that is solid in consistency and has a lobulated surface. Ranula is a translucent swelling in the mucosa of the oral cavity.
Premalignant tumors such as leukoplakia have as a smooth or wrinkled surface occurring as a patch or nodule on an erythematous base. Erythroplakia occurs as a red patch or plaque which is velvety and brighter than the surrounding mucosa. Leukoplakia may occur with interspersed erythroplakia as a fissured or erosive patch, while erythroplakia might also occur with interspersed leukoplakia. Melanosis or hyperpigmentation of the mucosa looks darker than the surrounding mucosa due to hyper secretion of melanin.
Carcinoma occurs as an ulcer which fails to heal or as a lump. Carcinoma of the lip may have an exophytic edge, meaning it grows outward with everted edges, or an ulcerative surface. Patients with carcinoma of the tongue usually present with a lump or irregularity on the surface of the tongue. If the tumor of the tongue is deep, the tongue keeps its surface integrity, but in cases of superficial lesion, it changes and loses its surface papilla, appearing smooth and shiny. Hard Palate carcinoma presents as an irregularity on the palate, which is felt by the patient. Later, as the tumor grows, it can fill the roof of the mouth.