Clinical Significance of Atypical Squamous Cells of Undetermined Significance among Patients Undergoing Cervical Conization

Background: Atypical squamous cells of undetermined significance (ASCUS) feature a wide variety of cervical cells, including benign and malignant examples. The management of ASCUS is complicated. Guidelines for office gynecology in Japan recommend performing a high-risk human papillomavirus (HPV) test as a rule. The guidelines also recommend repeat cervical cytology after 6 and 12 months, or immediate colposcopy. The purpose of this study was to determine the clinical significance of ASCUS. Materials and
Methods: Between January 2012 and December 2014, a total of 162 patients underwent cervical conization for cervical intraepithelial neoplasia grade 3 (CIN3), carcinoma in situ, squamous cell carcinoma, microinvasive squamous cell carcinoma, and adenocarcinoma in situ at our hospital. The results of cervical cytology prior to conization, the pathology after conization, and high-risk HPV testing were obtained from clinical records and analyzed retrospectively.
Results: Based on cervical cytology, 31 (19.1%) of 162 patients were primarily diagnosed with ASCUS. Among these, 25 (80.6%) were positive for high-risk HPV, and the test results of the remaining 6 patients (19.4%) were uncertain. In the final pathological diagnosis after conization, 27 (87.1%) and 4 patients (12.9%) were diagnosed with CIN3 and carcinoma in situ, respectively.
Conclusions: Although ASCUS is known as a low-risk abnormal cervical cytology, approximately 20% of patients who underwent cervical conization had ASCUS. The relationship between the cervical cytology of ASCUS and the final pathological results for CIN3 or invasive carcinoma should be investigated statistically. In cases of ASCUS, we recommend HPV tests or colposcopic examination rather than cytological follow-up, because of the risk of missing CIN3 or more advanced disease.