Comparison of different methods of fixation in Papanicolaou staining of cervical smears: Wet-fixation and rehydration of air dried smears

Abstract

Introduction: Cervical cancer is a major cause of death in women in all over the world. Cytological screening by Papanicolaou (Pap) smear had reduced significantly the occurrence of invasive cervical cancer. Obtaining a properly stained smear is needed for correct diagnosis which is often not possible due to improper fixation and drying artefacts. Objective: Our study tried to compare the morphology of the cervical smears fixed by two different fixation techniques, rehydration of air-dried smears (AD) versus wet fixation (WF). Design: This is a cross sectional study conducted in the department of pathology, Sree Narayana institute of medical sciences, Ernakulum, Kerala. Subjects: We collected cervical smears from three hundred patients in 24-72 years who attended our gynaecology department. Methods: Two slides are collected per patient. One of slides is immediately wet fixed in 95% ethanol (WF). The other slide was air dried and rehydrated for prior to routine staining by using glycerol saline rehydration method. Then the slides were stained by standard Papanicolaou method and paired slides were compared. Result: Most of the patients (51%) included in the study belonged to 35-45- years of age years, presented with complaints of discharge per vaginum. Air dried smears showed better cytoplasmic staining, distinct nuclear borders, clear background and low rate of cytolysis compared to wet fixed smears. Conclusions: Because of many advantages compared to the conventional wet fixation, air dried smears can be used routinely or as an alternative in mass cervical cancer screening programmes