Primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma.

Primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma is extremely rare, and the etiology of disease is not fully understood. We present herein the case of a primary hepatic MALT lymphoma with Helicobacter pylori and hepatitis C virus infection. A 71-year-old male was admitted to our institution to undergo a precise evaluation of a hepatic tumor incidentally detected during a computed tomography (CT) scan for chest examination. Dynamic CT showed faint enhancement during the arterial phase. The gadoxetate disodium-enhanced magnetic resonance imaging showed a hyper-intensity on the arterial phase and low intensity during the late and hepatocyte phases. Liver biopsy specimen showed small to intermediate size atypical lymphocytes with positive CD20 immunohistochemical staining. It was finally diagnosed as primary hepatic MALT lymphoma. FDG-PET/CT showed faintly increased uptake with a maximum standardized uptake value of 4.6, and did not show other pathological uptake. We present the rare case of primary hepatic MALT lymphoma and discussed the etiology of this disease.