Atrophy of the tympanic membrane denotes a thin and pellucid eardrum. Histologically, the atrophic area is characterized by a thin lamina propria, containing abnormally few elastic and fibrous fibers which make it thin, unelastic, and slack. In severe cases, the lateral part of the pars tensa consists exclusively of keratinized squamous epithelium and the medical part of flat, cuboid mucosal epithelium with the basement membrane, whereas the laminia propria is completely lacking. The antrophy may be diffuse or localized, and it may occur as the only pathological change or in connection with tympanosclerosis.