The diagnostic utility of cell block as an adjunct to routine cytology

Abstract

Despite the diagnostic utility of cell block in FNAC and fluid cytology, known for better cellular yield and improved diagnostic accuracy, the technique remains to be underutilized for diagnosing neoplastic lesions.In this paper, a hospital based prospective study of 195 samples was conducted on cytological samples with the aim (a) to evaluate the diagnostic utility of cell block as an adjunct to routine cytological evaluation of aspiration and effusion fluid specimens, (b) To correlate the findings of routine cytology, cell block and routine histopathological examination wherever possible and (c) to explore the possibility of using ancillary techniques such as immunohistochemistry on cell blocks. The study revealed, most of the patients were between 51- 60 years with female preponderance. Among 195 samples, 79 (40.5%) were peritoneal fluids and 85 (43.5%) were lymph node. The diagnosis on conventional smear and cell block showed 71 (36.5%) cases and 68 (35%) cases were negative for malignancy respectively. 6 (3%) cases and 4 (2%) cases were suspicious for malignancy respectively. 118 (60.5%) cases and 123 (63%) cases were positive for malignancy respectively. Amongst the peritoneal effusion the most common primary site was ovary whereas majority of the primary site was unknown in lymph node FNAC. Peritoneal effusion showed 8 additional cases as positive for malignancy in CB preparation which were negative or suspicious for malignancy on CS. In FNAC, two additional positive case was found in CB preparation of lymph node. A Kappa value of 89.5 % for statistical correlation between Conventional smear and cell block preparation was calculated. The use of Cell block technique increases the detection of malignancy when used as an adjunct to conventional smears. Cell block technique is simple, inexpensive and reliable adjuvant to smears and it is recommended for routine cytological diagnosis and for application of immunomarkers and molecular studies.