Objectives: Distinguishing koilocytes from their mimickers using Periodic acid-Schiff Stain. MATERIALS AND METHODS:This was a prospective analytical study. Data for the present study was obtained from the cervical biopsy specimens, received in the Department of Pathology, Mysore Medical College and Research Institute. Specimen received were fixed in 10% formalin and paraffin sections were prepared and stained with H&E for routine examination. The cases which showed koilocytic changes were stained with PAS Stain. Perinuclear vacuolation, nuclear changes and cytoplasmic characters were studied in both H&E and PAS-stained slides and the findings were recorded. RESULTS: A total of 432 cases of koilocytosis on H & E stain were included in the study. The age of the patients ranged from 29- 63 years with maximum number of cases between 3rd and 4th decade. Least number of cases were observed before 30 years of age. Additional sections were obtained for these 432 cases and were stained with PAS stain. Only 54 cases showed PAS positivity and the remaining were PAS negative. CONCLUSION: A diagnosis of koilocytes increases the need for frequent screening. But, overdiagnosis of HPV infection in cervical biopsies results in unnecessary diagnostic tests and surgical procedures, increased health care costs and mental trauma to the patient. Hence, HPV infection should be observed for a period of several months before definitive ablative treatment is undertaken.

Koilocytic change, HPV infection, Periodic acid Schiff stain (PAS)