Evaluation of diagnostic utility of imprint cytology in paediatric renal tumours with special references to Ki 67 proliferative marker

BACKGROUND: Pediatric renal neoplasms comprise about 7%–8% of all neoplasms in children. Wilms tumour (WT) is the most common among pediatric renal tumours. AIMS AND OBJECTIVES: The study was undertaken to study the epidemiological occurrence of pediatric renal tumours in a tertiary care hospital and to ascertain the validity and reliability of touch smear imprint cytology in intraoperative diagnosis of renal tumours and correlate with subsequent histopathological diagnosis and to assess the expression of proliferation marker Ki-67 in different components and stages of WT. MATERIALS AND METHODS: It was a single-institution-based prospective and observational study, conducted for 2 years (from October 2013 to September 2015) in the department of pathology at our hospital. A total of fifty cases were enrolled in this study, all were below 15 years of age. RESULTS: Imprint cytology showed sensitivity, specificity, and diagnostic accuracy of 83%, 98%, and 95.74%, respectively, in diagnosing benign and malignant renal tumours. There was statistically significant correlation of imprint cytology with confirmatory histopathological examination of excision specimen (P < 0.001). Immunohistochemical analysis of Ki-67 was done in all WT cases. Epithelial component had higher proliferative index than blastemal component with P = 0.0082, which was highly statistically significant. CONCLUSION: Imprint cytology is found to be a less expensive, simple, and rapid method, which can be used as an adjunct to histopathology. Correlation between proliferation index as measured with Ki-67 antibody and tumour stage was found. Ki-67 is thus a relevant marker for assessing the proliferative activity.