Cervical cytology/histology discrepancy: a 4-year review of patient outcome

To investigate the diagnosis, review and management of women identified as having a cytology/histology discrepancy.

A review of all patients diagnosed with a discrepancy between referral smear and cervical histology was performed between January 2003 and December 2004. Cases were followed for a minimum of 4 years and patient management and outcome reviewed.

A significant discrepancy was identified in 79 cases, 0.1% of all smears (n = 80,926) analysed during the study period. A discrepancy between cytology and histology, obtained from large loop excision of the transformation zone (LLETZ), was confirmed by multidisciplinary review in 42 cases (53.2%). In 37 cases (46.8%) the cytological and/or histological diagnosis was revised; the cytology was significantly more likely than the histology to be amended (chi square P = 0.005), most often because cytology had been overcalled. Of the confirmed discrepancy cases, 33 (78.6%) were due to high-grade squamous cell or glandular abnormalities on cytology with a negative, inflammatory or human papillomavirus (HPV) infection on histology (HGC/NH). HGC/NH cases were managed by cytological follow-up in 29 (87.9%), of which 72.4% of the smears were negative when performed at least 6 months post-excision. During the 4-year follow-up period six women with a confirmed HGC/NH underwent a repeat cervical excision (hysterectomy or LLETZ), and of these, HPV effect was seen in two cases but no cervical intraepithelial neoplasia was detected in any of the histological specimens.

Cytology overcall was responsible for the majority of cytology/histology discrepancies. A confirmed discrepancy is not an indication for a further excisional biopsy but follow-up is essential because a small percentage of patients may have disease that has been missed.