MOLECULAR CYTPATHOLOGY Section Editors: Dara Aisner, M.D. and Anders Hjerpe, M.D. Analysis of Morphological Markers of Chromosomal Instability in Ascitic Fluid Ruchita Tyagi, MBBS, MD, DNB, PDCC, 1 Pranab Dey, MBBS, MD, MIAC, FRCPATh, 2 * Radha Uppal, MSC, 2 and Arvind Rajwanshi, MBBS, MD, MIAC, FRCPATh 2 Chromosomal instability (CI) plays a major role in the carci- nogenesis. Micronuclei, nuclear budding, chromatin bridge- s,and multipolar mitoses are the morphological markers of CI and have never been studied in routine cytological specimens. Aims of the study is to analyze the significance of morphologi- cal markers of CI in malignant and benign ascitic fluid smears. A total of sixty benign and 40 malignant ascitic fluid samples were selected for this study. All the cases with malignant ascitic fluid showed histopathological evidence of malignancy in ovary and omentum. Chromatin bridges, multipolar mitosis (MPM), micronuclei and nuclear budding were counted in 1000 cells in representative May Grunwald Giemsa (MGG) stained smears. The CI markers were correlated with the cyto- logical diagnosis of effusion. The mean number of micronuclei, nuclear budding, chromatin bridge and multipolar mitoses found in malignant effusions were 13.2611.79, 10.1067.07, 2.5362.67, 1.964.5, respectively. The mean number of micro- nuclei, nuclear budding, anaphase bridges, and MPM found in benign effusion cases were 0.566761.07934, 0.516761.33, 0.66760.25, and 0, respectively. The student t test showed sig- nificant differences between malignant and benign ascitic fluid samples for each marker of CI. This is the first comprehensive study of morphological markers of CI in ascitic fluid smears. This study has shown strong correlation between markers of CI and cytological diagnosis of malignancy. In future, the knowl- edge of these markers can be applied to diagnose malignancy in suspected cases of effusion in difficult situations. Diagn. Cytopathol. 2015;00:000–000. V C 2015 Wiley Periodicals, Inc. Key Words: chromosomal instability; carcinoma; ascitic fluid; chromosomal bridge; micronucleus Chromosomal instability (CI) plays a major role in carcino- genesis. 1 The various sophisticated and expensive techniques like cytokinesis block, immunostaining with specific antibod- ies against centromeres, telomeres, DNA double stranded breaks, fluorescent and time lapse microscopy, flow cytome- try, fluorescent in situ hybridization and comparative genomic hybridization have been used to study CI. 2 The presence of chromatin bridges (CB), multipolar mitosis (MPM), nuclear budding and micronuclei on morphology has been proven to be an indicator of CI. 3 These markers of CI can help to distin- guish between benign and malignant effusions in difficult sit- uations. There have been very few studies on the significance of these morphological parameters as markers of CI. Dey et al. have studied the significance of micronuclei as marker of CI in effusions, urine smears and cervical smears. 4–10 There is no comprehensive study on the significance of combined morphological markers of CI in ascitic fluids. The aim of this study is to analyze the various morpho- logical markers of CI including CB, MPM, nuclear bud- ding, and micronuclei in ascitic fluid smears and compare their significance in malignant and benign cases. To the best of our knowledge, this is the first comprehensive cytological study to analyze morphological markers of CI in the ascitic fluid smears. Materials and Methods Ethical justification This is a retrospective study and the work was done on archival slides. No special test was done from the 1 Department of Pathology, Postgraduate Institute of Medical Educa- tion and Research, Chandigarh, India 2 Department of Cytopathology and Gynecological Pathology, Post- graduate Institute of Medical Education and Research, Chandigarh, India *Correspondence to: Dr Pranab Dey, MD, MIAC, FRCPath, Professor, Department of Cytopathology and Gynecological Pathology, Postgradu- ate Institute of Medical Education and Research, Chandigarh, India. E-mail: deypranab@hotmail.com Conflict of interest: There is no conflict of interest in this article Received 8 November 2013; Revised 12 November 2014; Accepted 17 December 2014 DOI: 10.1002/dc.23249 Published online 00 Month 2015 in Wiley Online Library (wileyonli- nelibrary.com). V C 2015 WILEY PERIODICALS, INC. Diagnostic Cytopathology, Vol. 00, No 00 1