Role of Hep Par1 Immuno marker for Cytological Differentiation between Primary and Metastatic Liver Cancer

Space occupying lesions of liver is a major health problem worldwide. Among them the most important is malignant SOLs. Discrimination between primary HCC and metastatic tumor is extremely important for treating the patient. For this purpose immunocytochemical technique can be applied on fine needle aspiration samples. Among the various immunological markers, the role of Hepatocyte Paraffin 1 antibody (Hep Par 1) is found to be very much convincing for its higher sensitivity and specificity. To categorize the malignant lesions into primary and metastatic by immunocytochemistry, this cytomorphological study was done on patients of radiologically diagnosed space occupying lesions of liver. The study population comprised of benign and malignant hepatic SOL cases attending at Department of Pathology and Hepatology, DMCH over a period of two years (July 2017 to June 2019). The total number of samples was 100. Fine needle aspiration was done and cell block was prepared from residual material. Immunocytochemistry with Hep Par1 was applied on cell block material of malignant lesions. Cytomorphological and immunocytochemical findings of each cases were documented in details. The data were collected and statistical analysis was done by SPSS. The mean age of study patients were found 47.0±13.37 years in benign and 53.63±10.89 years in malignant group with age ranging from 26 to 78 years. Male to female ratio was 4:1. According to cytomorphology, 32(50.8%) cases were diagnosed as hepatocellular carcinoma, 25(39.7%) as metastatic adenocarcinoma, 1(1.6%) metastatic small cell carcinoma and 1(1.6%) metastatic spindle cell sarcoma. According to immunocytochemistry, diffuse cytoplasmic granular staining with Hep Par1 were found in 26(81.3%) and no staining was seen in 24(88.9%) cases. Sensitivity, specificity, PPV, NPV and accuracy of HepPar1 for detection of hepatocellular carcinoma were 100%, 80%, 81.25%, 100% and 89.29% respectively. HepPar1 in conjunction to cytology is a very useful diagnostic modality in differentiating HCC from metastatic tumor in suspicious cases.