Clinical implication of atypical squamous cells of undetermined significance with or without favoring high-grade squamous intraepithelial lesion on cervical smears.

BACKGROUND: The cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS) on a cervical smear usually makes clinicians unsure of how to manage the patient and follow-up on her condition. We attempted to define the clinical implication of qualifying the cytologic diagnosis of ASCUS as either favoring a high-grade squamous intraepithelial lesion (HSIL) or not in an effort to provide management guidelines. METHODS: From January through May 1997, 65 of 5792 women who had cervical/vaginal smears taken at Kaohsiung Chang Gung Memorial Hospital were diagnosed as having ASCUS. Thirteen of the 65 cases of ASCUS favored an HSIL, based on nuclear abnormalities in atypical metaplastic and parakeratotic-type squamous cells. All these 65 patients were evaluated in our outpatient clinic by a second cervical smear, colposcopy, and colposcopically directed biopsies and/or endocervical curettage. The median length of the follow-up period was 19 months (range, 16 to 21 months). RESULTS: Of the 52 patients evaluated for ASCUS smears without favoring HSIL, 6 (11.5%) had a low-grade SIL (LSIL), 1 (1.9%) had cervical intraepithelial neoplasia grade II (CIN II), and 1 (1.9%) had invasive squamous carcinoma. Of the 13 patients with a cervical cytologic diagnosis of ASCUS favoring HSIL, 1 (7.6%) had immature metaplasia, 2 (15.4%) had LSIL, 2 (15.4%) had CIN II, 6 (46.2%) had CIN III, and 2 (15.4%) had invasive squamous carcinoma. CONCLUSION: For patients with a cytologic diagnosis of ASCUS favoring HSIL, more aggressive interventions, such as colposcopy-directed biopsy, endocervical curettage, or even conization, should be performed promptly. However, those without features favoring HSIL may be evaluated with regularly repeated smears.