Eliminating the diagnosis atypical squamous cells of undetermined significance: impact on the accuracy of the Papanicolaou test.
OBJECTIVE
To assess eliminating the diagnosis "atypical squamous cells of undetermined significance" (ASCUS) from the Bethesda System for Reporting Cervical/Vaginal Cytological Diagnoses and analyze its impact on the sensitivity and positive predictive value of Pap smears.


METHODS
A total of 166 previously diagnosed ASCUS cases with follow-up biopsy results available were prospectively downgraded to within normal limits/benign cellular changes or upgraded to specific squamous intraepithelial lesions (SILs) or the malignant category. These review cytodiagnoses were compared with the histologic outcome. The impact on the sensitivity and positive predictive value of Pap smears was also assessed.


RESULTS
Though there was a decrease in the sensitivity of the Pap smear from 100% to 76.3% for SIL overall and from 100% to 80% for high grade SIL (HSIL) alone, there was an improvement in the positive predictive value of diagnosing SIL from 46% to 85% and from 6% to 15% for HSIL alone.


CONCLUSIONS
The ASCUS diagnosis can be minimized to a great extent, if not eliminated completely. The "ASCUS-favor reactive" group can be eliminated, while the diagnoses "ASCUS favor SIL" and "ASCUS-not otherwise specified" should be used sparingly.
Sodhani
Pushpa
P
Division of Cytopathology, Institute of Cytology and Preventive Oncology, Maulana Azad Medical College Campus, Bahadur Shah Zafar Marg, New Delhi, India. psodhani@yahoo.com
Gupta
Sanjay
S
Singh
Veena
V
Sehgal
Ashok
A
Mitra
Ardhendu Bikash
AB
D002277:Carcinoma / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D003951:Diagnostic Errors / Q000517:prevention & control*; D004847:Epithelial Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D008679:Metaplasia / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000473:pathology; D065006:Papanicolaou Test; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000473:pathology*; D014626:Vaginal Smears / Q000592:standards*