Comparison of Staining Characteristics of Papanicolaou Stain and May-Grünwald-Giemsa Stain in Tzanck Smear Cytology

Introduction: Although the skin is more readily accessible to the cytological examination than any other organ, cytodiagnosis is much less frequently used in dermatology. Tzanck smears are routinely stained with May-Grünwald-Giemsa (MGG) stain. But, Papanicolaou (PAP) stain is known to yield polychromatic transparent staining with crisp nuclear and cytoplasmic features. Aim: To compare the staining characteristics of PAP stained and MGG stained Tzanck smears by using a scoring system. Materials and Methods: The present study was a cross- sectional study on Tzanck smears, conducted at a tertiary care referral Institute, PES Institute of Medical Sciences and Research (PESIMSR), Kuppam, Andhra Pradesh, India, from March 2016 to April 2017. In each case, two Tzanck smears were prepared. One smear was wet-fixed in isoproplyl alcohol and stained by PAP method. The other smear was air-dried and stained by MGG stain. Both the smears were evaluated for the staining characteristics by using a scoring system. The scoring system was indigenously designed for evaluating the stained sections. All the staining parameters such as contrast, cytoplasmic features, nuclear features and background were evaluated in the scoring system employed in the present study. Chi-square test and two sample t-test were used for statistical analysis. Results: Forty cases of Tzanck smears were analysed. Most common diagnostic entity was cutaneous infections in 18 cases (45%). The average scores of all the parameters of staining characteristics and the overall score were better in PAP stained smears than MGG stained smears. The p-values were statistically significant. Conclusion: PAP stain may be considered as a behooveful stain for the evaluation of Tzanck smear. It may be suggested that, although the PAP stained smears scored better than MGG statistically, both the stains may be used as complementary to each other.