Presence of koilocytosis in low-grade smears of high-risk HPV-positive women is a negative predictor for cervical intraepithelial neoplasia grade 3 or more.

OBJECTIVE: The Netherlands converted to high-risk (hr)HPV-based screening in 2017. An increase in referral of hrHPV-positive women with low risk for cervical intraepithelial neoplasia grade 3 or more (CIN3+) is anticipated and reduction of unjustified referrals will have priority. The relevance of koilocytosis in relation to the underlying risk of high-grade CIN in a primary HPV screening setting is unclear. The aim was to investigate whether the risk for CIN3+ differs between hrHPV-positive atypical squamous cells of undetermined significance (ASC-US)/low-grade squamous intraepithelial lesion (LSIL) with or without koilocytosis. METHODS: Retrospective cohort study, using data from the Dutch national pathology database (PALGA). The population was 1201 hrHPV-positive women with cytological diagnosis of ASC-US/LSIL. Reporting of koilocytosis was assessed as well as detection rates of CIN1 or less, CIN2 and CIN3+ for ASC-US/LSIL cytology stratified by presence or absence of koilocytosis. Crude and adjusted odds ratios were determined. RESULTS: Koilocytosis was present in 40.1% of ASC-US and 45.9% of LSIL cases. CIN3+ is significantly less often found when koilocytosis is present (7.8% for hrHPV-positive ASC-US with- vs 15.8% without koilocytosis). For hrHPV-positive LSIL this was 11.7% vs 20.2%. The crude and adjusted odds ratios for CIN3+ was 0.45 for hrHPV-positive ASC-US and 0.52 for hrHPV-positive LSIL. CONCLUSIONS: The presence of koilocytosis is a negative predictor of CIN3+. The risk of hrHPV-positive ASC-US with koilocytosis is in the same range as hrHPV-positive/cytology negative cases and in a setting of primary hrHPV screening these cases could be followed conservatively by repeat cytology. The results should be confirmed by the first data from the Dutch HPV-based screening programme.

Accurate assessment of cell density in low cellular liquid-based cervical cytology.

OBJECTIVE: Scant cellularity is the most important source of unsatisfactory liquid-based cytology. Although still being debated, low cellularity is thought to compromise the detection of squamous lesions. Thus, reliable assessment of cellularity is essential. The aim of the present study was to determine the cellularity range for ThinPrep(®) slides of low cellularity and to establish the most accurate cell-counting protocol. METHODS: A series of 60 ThinPrep cases representing the full spectrum of adequate, 'satisfactory but limited by' (SBLB) and unsatisfactory reports were included. Two cell-counting protocols with three different magnifications, using ×10, ×20 and ×40 objectives, were evaluated and related to the true cellularity, together with a reassessment of the degree of adequacy originally reported. The cell-counting protocol that showed the highest correlation coefficient was considered the most accurate. RESULTS: Based on seven (re)assessments a majority score for adequacy was established. There were 42 cases with a majority score 'unsatisfactory' or 'SBLB' (low cellularity) of which 41 contained fewer than 20 000 squamous cells; and 18 cases with a majority score 'satisfactory' of which one had fewer than 20 000 cells. The cell-counting protocol that showed the significantly highest correlation with the reference standard was the Stichting Kwaliteitsbewaking Medische Laboratoriumdiagnostiek (SKML) protocol with a ×10 objective. CONCLUSIONS: ThinPrep slides reported as unsatisfactory or SBLB were shown to contain fewer than 20000 squamous cells. The most accurate protocol for estimating the cellularity of these slides was cell counting in five non-adjacent microscope fields along the horizontal axis and five along the vertical axis of the slide with a ×10 objective and applying a correction factor of 1.24× to correct for underestimation of the true cellularity.

Cytology of the vulva: feasibility and preliminary results of a new brush.

OBJECTIVE: Taking a biopsy is a standard procedure to make the correct diagnosis in patients with suspicious premalignant vulvar lesions. The use of a less invasive diagnostic tool as triage instrument to determine whether biopsy is necessary may improve patient comfort especially in patients with chronic vulvar disorders that may warrant consecutive biopsies. This study was conducted to investigate whether vulvar brush cytology is feasible and may be used to detect (pre)malignant vulvar lesions. METHODS: A pilot study was performed with patients having clinically normal vulvar skin, lichen sclerosus (LS), usual or differentiated vulvar intraepithelial neoplasia or squamous cell carcinoma. A total of 65 smears were taken with the use of a vulvar brush and biopsies were performed for histopathological analysis. RESULTS: Out of 65 smears, 17 (26%) were discarded because of poor cellularity. A total of 28 of 29 (97%) smears with a histological proven (pre)malignancy had a smear classified as 'suspicious' or 'uncertain'. Cytology classified 11 smears as 'non-suspicious', of which 10 (91%) were indeed normal skin or LS. The accuracy, based on the presence of a lesion, for (pre)malignant lesions with the use of the brush showed a sensitivity of 97% and a negative predictive value of 88%. CONCLUSION: Vulvar brush cytology is feasible and may be a first step in the development of a triage instrument to determine whether subsequent biopsy of a clinically (pre)malignant lesion is necessary.