Primary Hepatic Carcinosarcoma: A Rare Diagnosis With Unique Morphology

Abstract Introduction/Objective The terminology and pathogenesis of primary hepatic carcinosarcoma remain controversial, as they are less than 1% of all hepatic cancers. The diagnostic challenges include interpreting their distinct morphology, immunohistochemical staining and excluding the differential diagnosis. Methods/Case Report Our case is of a 72-year-old man with history of smoking and occasional alcohol use. There was no history of viral hepatitis. He came with the complaint of abdominal pain and found to have 20 cm confluent mass in the left lobe of liver on imaging studies. Needle core biopsy was performed on the liver mass and showed biphasic malignant neoplasm with geographic necrosis. The tumor displayed two distinct patterns of growth. Portions of tumor exhibit vesicular nuclei with prominent nucleoli and abundant granular cytoplasm forming sheets and pseudoglandular structures. There were also separate well-demarcated foci of undifferentiated malignant epithelioid to spindle cells with abundant mitosis and apoptosis. The areas of hepatocellular differentiation were positive for Hep- Par-1, arginase and cytokeratin cam 5.2 and weak staining for glypican-3. They were negative for vimentin and smooth muscle actin. In contrast, the undifferentiated component is negative for Hep-Par-1, arginase, cytokeratin cam 5.2 and positive for vimentin (but not smooth muscle actin). The morphology and immunohistochemical staining pattern were consistent with a hepatic carcinosarcoma with undifferentiated sarcomatous component. The patient was put on palliative care due to the advanced nature of his disease. Results (if a Case Study enter NA) NA. Conclusion Despite the advancements in diagnostic techniques and treatment modalities, hepatic carcinosarcoma still is a rare occurrence with very dismal prognosis.