Dysplasia of oral mucosa: a unified approach to proper evaluation.

The histologic features of fully developed epithelial dysplasia of oral mucosa are readily recognized. Early dysplastic change, however, may present a diagnostic challenge since its frequently subtle features may, on occasion, cause it to be overlooked and thus undercalled. The problem of underdiagnosis is further compounded in many instances by the markedly diverse manner in which altered surface epithelium is described, interpreted, and reported. In an effort to establish a more unified manner of histopathologic interpretation of oral epithelial tissue, we propose clear definitions for the terms atypia, dyskeratosis, dysplasia, and lichenoid, underscoring topographic as well as morphological criteria for each. Significant alterations in rete ridge architecture and maturation disturbance are identified as subtle yet important markers of dysplastic potential, even in the absence of atypical cytomorphology. Correlation of clinical and historical data with microscopic findings is also stressed as an important adjunct to the arousal of diagnostic suspicion. Interpretative rationale and an illustrative case are offered in support of points raised.