Formalin Sediment Cytology of Small Biopsy Samples: An Adjunct to Histopathology

Abstract

Introduction: Cytological evaluation of malignant neoplasms forms an integral part of diagnostic work-up in any malignant disorders. Sediment cytology or more aptly called as biopsy sediment cytology is a technique that involves study of smears prepared from sediment of biopsy specimen fixatives. The preliminary diagnosis on sediment cytology helps in planning and early initiation of treatment. Aim: To evaluate the cytomorphological features of sediment cytology of small biopsy samples and compare the same with histopathological diagnosis. Materials and Methods: A cross-sectional study was conducted over a period of two months from July to August 2021 at ESIC Medical College and PGIMSR, Bengaluru, Karnataka, India. A total of 51 samples were included for the study. The sediments of biopsy specimens were collected in a test tube, centrifuged at 2500 rpm for 10 minutes and smears were prepared. Stained smears were evaluated for presence and morphology of cells. The morphology was compared with histopathological diagnosis of biopsy specimens. The concordance rate was assessed by Pearson’s correlation coefficient in non neoplastic/benign lesions and malignant lesions separately. A p value of <0.05 was taken to be statistically significant. Results: Biopsies from gastrointestinal system accounted for the maximum number of 16 (31.4%) cases, followed by biopsies from oral cavity 15 (29.4%) cases and female genital tract 11 (21.5%) cases. Sediment cytology yielded diagnostic material in 46 (90.2%) cases. The diagnostic yield was 90.2% with an overall concordance of 60.8%. The sensitivity, specificity and diagnostic accuracy was 65.12%, 100% and 60.8%, respectively. The concordance rate in non neoplastic/benign lesions was r=0.99, with p=0.0001, whereas with respect to malignant lesions, concordance rate was r=0.86 with p=0.0003. Conclusion: Cytological evaluation plays an important role in early and effective planning of appropriate treatment. Biopsy sediment cytology although an adjunct to histopathology has practical utility and fulfills the desired role of any cytological sample in providing a provisional diagnosis.

Keywords

• cytomorphological evaluation
• diagnostic yield
• exfoliated cells
• malignant neoplasms
• preliminary diagnosis
• technique