Utility of guided FNAC and cell block preparation from liver and gall bladder masses: Learning experience from a tertiary care center.

Introduction: Ultrasound- and CT-guided fine needle aspiration cytology (FNAC) increases the accessibility of intra-abdominal masses to the liver and gall bladder with the advantages of low cost and high diagnostic yield. Cell block technique has been known for further increasing the diagnostic accuracy.

Aims and objectives: We aimed to study the effectiveness of FNAC and the cell block method in cytological diagnosis of liver and gall bladder masses. We also followed a step-wise approach to increase the success rate.

Materials and methods: A 2-year observational study was done from July 2020 to June 2022. Total 80 guided (CT and ultrasound) aspirations were done from space occupying/mass lesions in the liver [74 (92.5%)] and gall bladder [6 (7.5%)], out of which cell blocks by the plasma thrombin method were prepared in 12 cases (15%). The on-site radiological details were noted, and rapid on-site evaluation was done in 65 cases (81.25%). The prepared cytology slides were stained with Papanicolaou, H and E and May-Grunwald Giemsa (MGG) stain. The cytological diagnosis was noted, and the uses and limitations (if any) were observed in each case. A step-wise structured questionnaire format was developed to assist the reporting pathologist so as not to miss out on important diagnostic observations, if present.

Results: FNAC in 71 cases (88.7%) gave a conclusive diagnosis. The maximum number of cases were of adenocarcinoma [38 (51.3%)] from the liver followed by hepatocellular carcinoma in 10 cases (13.5%). In gall bladder masses, all 6 cases (100%) were positive for malignancy, out of which 4 cases (66.7%) could be characterized as adenocarcinoma. The cell block preparation was helpful in reaching the diagnosis as well as typing the malignancy in 10 cases (83.3%). The chief limitation observed on conventional cytology smears was inadequate cellularity, which caused inconclusive diagnosis in 9 cases (11.25%). The reporting questionnaire was helpful chiefly in terms of time-efficient reporting in 34 cases (42.5%), increasing the ease and confidence in 69 cases (86.25%) and the advantage of reproducibility of data in all cases (100%) according to the case-by-case evaluation by the reporting pathologists.

Conclusion: Guided FNAC in conjunction with the cell block technique is extremely helpful in the evaluation of mass lesions of the liver and gall bladder for cytological diagnosis. A proper step-wise approach may be useful to reach a quick and effective diagnosis.