The significance of atypical squamous cells of undetermined significance in Barbados - Poster abstract

OBJECTIVE: To evaluate the significance of a Papanicolaou (Pap) cervico-vaginal smear diagnosis of atypical squamous cells of undertermined significance (ASCUS) using cytohistologic correlation and to determine the ASCUS squamous intraepithelial lesions (SIL) ratios of five cytopathology laboratories. DESIGN AND METHODS: A combined retrospective and prospective study was undertaken to evalute the histologic diagnoses of the biopsies from patients who attended the colposcopy clinic at the Queen Elizabeth Hospital with the Pap smear cytologic diagnosis of ASCUS during the period, January 1 - April 15, 1998. The laboratory from which the Pap reports were issued was recorded. RESULTS: During this three and a half month period three hundred and sixty-four (364) patients with abnormal smears diagnosed at five different cytology laboratories were investigated. One hundred and fifty (42.1 percent) patients has a Pap smear diagnosis of ASCUS, followed by 161 (46.5 percent) SIL, 130 (35.8 percent) wit low grade intraepithelial lesions (LSIL) and 31 (10.7 percent) high grade intraepithelial lesions (HSIL). Three cases with ASCUS were subsequently excluded from the study because of insufficient data. The histologic diagnosis of the remaining 147 biopsies from patients with the Pap smear diagnosis of ASCUS were LSIL 49 (33.6 percent), HSIL 9 (6.2 percent), atypia/metaplasia 66 (45.2 percent) and inflammation/normal 23 (15.1 percent). The overall ASCUS/SIL ratio was 0.90 and the individual laboratory ratios ranged from 0.25 to 1.70 with a mean of 0.84 ± 0.63. CONCLUSION: The histologic diagnosis of a cervical cytologic smear assessed as ASCUS may vary from normal to HSIL. Just under 40 percent are likely to be SIL with LSIL predominant. The ASCUS/SIL ratios of Barbadian cytopathology laboratories are less than the ASCUS/SIL ratio (2.0-3.0) suggested by the 1992 NCI Workshop at Bethesda. Hence a diagnosis of ASCUS in Barbados requires careful follow-up.(AU)