ThinPrep processing of endoscopic brushing specimens.

To evaluate ThinPrep (Cytyc, Marlborough, MA) processing of endoscopic brushing specimens for cytologic examination, ThinPrep slides and direct smears of 29 gastrointestinal (GI) and 22 bronchial brushings were compared. Clinicians prepared the direct smears. The brush was then immersed in CytoLyt (Cytyc) and one ThinPrep slide made. All cases had corresponding biopsies. Smears and ThinPrep slides were screened and reviewed independently. Screening time per case was recorded. All slides were evaluated for cellularity, quality, cellular preservation, and quantity of diagnostic cells. A diagnosis was rendered for each case. Cytologic and histologic diagnoses were correlated. Follow up was obtained for cases with discrepant histologic and cytologic diagnosis. Twenty-three brushings were from esophagus, 5 stomach, 1 duodenum, and 22 lung. An average of 3.6 direct smears (range 2-6) was made for each case. Average screening time per case was 12 minutes for GI direct smear, 15 minutes bronchial direct smear, 4 minutes GI ThinPrep slide, and 9 minutes bronchial ThinPrep slide. ThinPrep slides were superior to direct smears in cellularity, quantity of diagnostic cells, and quality of slides. ThinPrep slides and direct smears showed comparable cellular preservation. The sensitivity of detecting malignancy by biopsy, direct smears, and ThinPrep slides was 81%, 75%, and 75%, respectively. One false-positive diagnosis was made on cytology with both direct smear and ThinPrep slide, a case with radiation atypia. In conclusion, ThinPrep slides are at least comparable to direct smears in cytologic examination of brushings. However, false-positive diagnosis is a possible potential pitfall.

Histocytological study of squamous atypia on Pap smears.

UNLABELLED: The significance of squamous atypia on Pap smears is currently unclear and its management is controversial. We undertook this study to determine whether cytological parameters on Pap smears with a diagnosis of squamous atypia could be useful in predicting the presence of a squamous intraepithelial lesion (SIL). METHODS: For a 3-mo period, all patients who had a colposcopically directed biopsy and or endocervical curettage (ECC) with a simultaneous or a previous Pap smear showing squamous atypia were identified. All biopsies were reviewed and all cytological smears were evaluated for the following cytological parameters: inflammation, parakeratosis, atypical parakeratosis, number of atypical cells, nuclear size, chromatin pattern (fine, coarse, or hyperchromatic), as well as presence of metaplasia, nuclear membrane irregularity, multinucleation, and nuclear halo in the atypical cells. RESULTS: a total of 97 patients were eligible for the study. The average interval between the Pap smear and colposcopy was 96 days (range, 0 to 364 days). Thirty patients (31%) had SIL on biopsy or ECC, of which 17 (18%) were SIL, low grade, and 13 (13%) were SIL, high grade. Of the 67 that showed no SIL on histology, 24 had inflammatory reactive changes, five had squamous metaplasia with atypia, one had parakeratosis, and 37 had essentially normal biopsies. Most of the cytological features, except coarse chromatin, were equally predictive of SIL with approximately 30% of the patients with any particular feature showing SIL on histology. However, 46% (17/37) of those that had coarse chromatin showed SIL on histology (P < 0.02). Based on this study, squamous atypia on Pap smears appears a marker of an underlying SIL in a considerable number of cases, and coarse chromatin seems most helpful in predicting the presence of SIL.