Cell recovery and appearance in thin-layer preparations in nongynecologic cytology

To compare the diagnostic efficacy of a thin-layer technique with that of a membrane filter technique using a wide variety of fresh cytologic specimens.

Paired samples from 272 nongynecologic cytology specimens were processed for microscopy using thin-layer and membrane filter preparation techniques. Specimens included 162 body fluids and urines, 32 bronchial aspirates and 78 fine needle aspiration biopsies. The two techniques were compared for diagnostic efficacy, cell density/specimen, cell types recovered, qualitative cytomorphology, ease of interpretation and long-term stability of the final preparations.

Diagnoses supported by filter preparations were also supported by their matched thin-layer preparations. The same cell types were recovered by both techniques, and the slide cell density was slightly greater using membrane filters. Qualitative morphology and ease of use were superior with the thin-layer samples. After two years, all thin-layer slides were stable and readable, whereas only 43% of the membrane filter slides were usable.

Thin-layer techniques are morphologically comparable and, in some ways, superior to membrane filter techniques for processing a wide variety of nongynecologic cytology specimens.