Imprint cytology of ameloblastoma.

To reveal the characteristic features of the imprint cytology of ameloblastomas, we compared these features with the histopathological features of the same specimens. Twenty-five cases, histopathologically diagnosed as ameloblastoma, were used. Three cell types were recognized: small squamous epithelial cells which were polyhedral or spindle-shaped with some projections; naked cells with poorly defined cytoplasm showing tubular and palisade patterns in some areas; and large squamous epithelial cells with extensive wrinkled cytoplasm. Naked cells and small squamous epithelial cells were thought to correspond to the histopathological classifications of cuboidal to columnar cells, and polyhedral or spindle cells respectively. Large squamous epithelial cells were thought to be acanthomatous cells showing squamous metaplasia. Imprint cytology had characteristic advantages compared to fine needle aspiration cytology, and clearly reflected the histopathology of the lesions. Knowledge of the characteristic features of the cells observed in imprint cytology is important when undertaking cytodiagnosis using fine needle aspiration.