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

OBJECTIVE: To investigate the diagnosis, review and management of women identified as having a cytology/histology discrepancy. METHODS: 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. RESULTS: 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. CONCLUSION: 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.