Casts and crusts of the tympanic membrane

Casts and crusts of the tympanic membrane were removed from patients with previous otitis media. Casts are formed of adherent keratinocytes in a matrix of dried exudate. Detachment from the drumhead leaves the underlying epidermis intact. Casts are defined as those crusts that have detached spontaneously from the surface of the drum. A mechanism based on epithelial proliferation induced by inflammation within the middle ear, with subsequent keratinocyte retention and thickening, is proposed.