Primary Hepatic Mucosa-associated Lymphoid Tissue Lymphoma Mimicking Cholangiocarcinoma: Report of a Case

Abstract

Primary hepatic marginal zone B-cell lymphoma of the mucosa associated lymphoid tissue (MALT) is an extremely rare disease. We report the case of an 80-year-old man presenting with a huge hepatic mass in the left lobe. The mass measured approximately 10 cm and appeared with mixed echogenicity on sonography. The laboratory and imaging studies suggest cholangiocarcinoma. Sono-guide fine needle biopsy revealed a picture of chronic granulomatous inflammation. We performed laparoscopic biopsy to clarify the discrepancy between clinical histology and fine needle biopsy. The histology of laparoscopic biopsy showed dense infiltration of smallsized lymphocytes, centrocyte-like (marginal zone) and monocytoid cells with immunostaining positive for CD 20 and focally positive for CD 21 suggestive of primary hepatic MALT lymphoma. There was no evidence of lymphoma involvement at other sites. The pathogenesis of primary hepatic MALT lymphoma remains unclear; however, previous studies suggested the role of chronic inflammatory disease. Diagnosis of primary hepatic MALT lymphoma might require adequate amount of liver tissue and immunostaining.