Clinical Pathological Factors of Hepatic Inflammatory Pseudotumor-like Follicular Dendritic Cell Tumor

ObjectiveTo investigate the clinicopathologic features of hepatic inflammatory pseudotumor-like follicular dendritic cell tumor (IPT-like FDCT)，and to conclue the diagnostic and differential diagnostic criteria for these morphologically similar tumors. Methods One case of hepatic IPT-like FDCT，seven cases of hepatic inflammatory myofibroblastic tumor(IMT),one case of primary hepatic Hodgkin lymphoma（HL）and one case of primary hepatic malignant fibrous histiocytoma (MFH) were analyzed by routine histopathological，immunohistochemical staining and in situ hybridization for Epstein-Barr Virus(EBV)-encoded RNA(EBER). Results The hepatic IMT，primary hepatic HL and primary hepatic MFH were mimicking hepatic IPT-like FDCT in many ascpects of clinicopathologic features.However，hepatic IPT-like FDCT had no any symptom or right upper quadrant pain，hepatomegaly，fever and weight loss . The tumor is solitary and well demarcated from surrounding parechyma. Histologically，Tumor cells were composed of oval-to-spindle cells arranged in diffuse，vague storiform，fascicular and spindle cells were dispersed in a background of abundant inflammatory cells，predominantly lymphocytes and plasma cells.The cells possessed enlarged，sometimes twisted or irregularly folded，nuclei that contained vesicular chromatin，and small but distinct,centrally located nucleoli. Sometimes Reed-Sternberg-like giant cells were encountered.Immunohistochemically，the tumor calls were positive for CD21and CD35，and were also positive for EBV-encoded RNA by in situ hybirdization. Conclusion sThe hepatic IPT-like FDCT is a rare neoplasm.The penal of immunohistochemical markers and EBER are necessary for the final diagnosis of these tumors because of the complexity and similarity of different tumors of this kind.