Pseudolymphoma (Reactive Lymphoid Hyperplasia) of the Liver Containing Epithelioid Cell Granulomas and Schaumann's Bodies in Giant Cells

Nodular lymphoid hyperplasia, also known as pseudolymphoma (PL), of the liver is a benign reactive process of lymphoid tissue and is extremely rare. To our knowledge, only four cases of hepatic PL have been reported to date. We present a 59-year-old woman patient with hepatic PL that was preoperatively diagnosed as hepatocellular carcinoma (HCC), based on the findings of a variety of imaging modalities. However, resection of the tumor specimen at hepatic lobectomy revealed that the tumor was not a true tumor but a PL composed of proliferated nonneoplastic, polyclonal lymphocytes and plasma cells with abundant lymphoid follicles, together with mononuclear and multinuclear histiocytes with granuloma formation. Sporadic multinucleated giant cells had concentrically or eccentrically laminate ‘conchoidal’ bodies, known as Schaumann's bodies. Immunohistochemical staining of lymphocytes and plasma cells for T and B cells, or IgGK and IgGk revealed the polyclonal nature of these cells. Furthermore, clonal immunoglobulin heavy-chain gene rearrangement was not detected in the lymphoid cells in the lesion with polymerase chain reaction (PCR) analysis. The background hepatic tissue showed no cirrhosis, but some lymphocytes had infiltrated into the portal tracts around the tumor. Since hepatic PL is extremely rare and no association of PL with granuloma with Schaumann's bodies has been described in previously reported cases with hepatic PL, the clinical and histologic features in this case are described with a literature review.