A 78-year-old Japanese man was referred to our hospital after experiencing black feces. No abnormal finding was detected in the endoscopic examination of his stomach and large intestines. Computed tomography (CT) of the abdomen revealed a tumor lesion in the right lobe of the liver. A needle biopsy of the tumor under ultrasound guidance was performed. A pathological examination of the biopsy specimen showed a diffuse proliferation of lymphoma cells, which was compatible with diffuse large B-cell lymphoma (DLBCL). F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)-CT demonstrated increased FDG uptake only in the liver tumor. We made the diagnosis of primary DLBCL of the liver. After six cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP), the patient achieved complete remission and has maintained remission for 2 years since the diagnosis. The R-CHOP regimen might be effective therapy for primary DLBCL of the liver.
びまん性大細胞型Ｂ細胞リンパ腫（diffuse large B-cell lymphoma）