Cell block preparation as a diagnostic technique complementary to fluid-based monolayer cervicovaginal specimens

OBJECTIVE: To determine whether preparation of cell blocks from fluid-based cervicovaginal specimens can add to the diagnostic accuracy of monolayer p reparations from the same specimens. STUDY DESIGN: Cell block preparations were made from 100 cervicovaginal, fl uid-based ThinPrep Pap test specimens. These specimens were collected in a fluid-based solution with a Papette or cytology brush and a scraper. After a monolayer slide was mane, a determination teas made if a cell block prepa ration was needed based on the morphologic findings on the slide. RESULTS: Cell block results aided the ThinPrep Pap diagnosis in 20% of spec imens and were critical to the diagnosis in 5%. The cell block preparation was most useful in lesions where architecture and morphology were important , such as immature squamous metaplasia versus high grade squamous intraepit helial lesion, repair versus squamous carcinoma and tubal metaplasia versus atypical glandular cells of undetermined significance. It was also found t hat the presence of tissue fragments rather than single cells on the slide was an indication of the possibility that a cell block teas productive. CONCLUSION: Cell block preparation in selected cases can be a valuable adju nct to monolayer slide preparations in the diagnosis of cervicovaginal lesi ons.