Follicular dendritic cell tumor of the liver associated with Epstein-Barr virus.

Follicular dendritic cell tumors are an uncommon neoplasm. About half of all cases occur in the lymph nodes, especially in the neck region. Follicular dendritic cell tumors of the liver are even rarer. In this article we report a case of a hepatic follicular dendritic cell tumor. A 30-year-old female was noted to have a hepatic mass 6 cm in size in segment 6. The patient underwent a right lobectomy of the liver. Microscopically, the lesion was an admixture of spindle cells and inflammatory cells, chiefly lymphocytes, plasma cells, histiocytes and a few neutrophils. The spindle cells were arranged in a wavy pattern, with a vague cellular border and eosinophilic cytoplasm. These tumor cells were immunoreactive to CD21 and CD68. The test for Epstein-Barr virus (EBV)-encoded nuclear RNAs using in situ hybridization was also positive. Although hepatic follicular dendritic cell tumors appear similar to conventional inflammatory pseudotumors in terms of histology, they should be regarded as a clonal proliferation of follicular dendritic cells. In contrast to follicular dendritic cell tumors in extrahepatic areas, hepatic follicular dendritic cell tumors have a strong association with EBV and a greater inflammatory component and are more prevalent in females.