DIAGNOSTIC UTILITY OF CELL BLOCK AS AN ADJUNCT TO FINE NEEDLE ASPIRATION CYTOLOGY

Abstract

Background: Fine needle aspiration cytology (FNAC) has proven to be very effective means of obtaining tissues from different body sites for diagnosis. However, in order to overcome its disadvantages including availability of limited material, lack of tissue architecture, overcrowding and paucity of representative cells, cell block (CB) technique has been resorted to make the best use of available material. Cell block sections bridge the gap between cytology and histopathology and can be utilized for routine stains, special stains and immune histochemical (IHC) analysis.
Objective: To assess the utility of cell block technique in increasing the sensitivity of cytodiagnosis of fine needle aspiration samples and to study the correlation of the results obtained from cell block technique with conventional cytological smears.
Study design: This was a prospective observational study conducted over a period of one and a half years.
Participants: 100 patients.
Method: FNAC smears and CB sections were prepared for all cases and diagnostic accuracy was analysed.
Results: Out of the total 100 cases maximum number of aspirations were non-guided i.e. 59 cases followed by 29 cases of USG guided and 12 cases of EBUS-TBNA. In 91 cases both FNAC smears and cell blocks were adequate, while in 5 cases only FNAC smears were adequate and in 4 cases only cell blocks were found to be adequate. On statistical analysis, cell block increased the overall sensitivity of FNAC smear diagnosis by 18.1% and accuracy by 14.5%. On statistical analysis, the combined use of FNAC and cell block increased sensitivity by 19.5% and accuracy by 15.6%.
Conclusion: The study revealed that FNAC smears and CB’s complement each other and combining both the tests improves the diagnostic yield and facilitates accurate diagnosis.
Implication: Diagnostic adjunct to FNAC for ancillary techniques.