The conceptual view of natural killer (NK) cell malignancies has recently undergone a significant evolution. The majority of such diseases are associated with Epstein-Barr virus (EBV), while only a limited number of EBV-negative cases has been reported. We report an unusual case of NK cell lymphoma/leukemia showing a monomorphic histology, absence of intracytoplasmic azurophilic granules, and no EBV association. The patient was a 57-year-old woman who died 26 months after the diagnosis. Autopsy revealed tumor infiltration in the liver, spleen, lymph node, blood, and bone marrow. There was no involvement of the skin or nasal cavity throughout the clinical course. The tumor showed the monotonous proliferation of medium-sized cells without intracytoplasmic azurophilic granules. Phenotypic analysis showed CD2+, CD3/Leu4–, cytoplasmic CD3ε+, CD4–, CD5–, CD7+, CD8–, CD16–, CD38+, CD56+, CD57–, TdT–, granzyme B–, and TIA1+ phenotype. There were no detectable rearrangements of T cell receptor genes or immunogloublin heavy chain genes. Furthermore, there were no EBV-encoded small RNAs. These findings provide information to improve the understanding of poorly defined entities, i.e. aggressive NK cell lymphoma/leukemia and blastic NK cell lymphoma/leukemia.

No abstract

Primary hepatic lymphoma is a rare disorder and the clinical behavior remains unknown. We report a patient with primary hepatic lymphoma who had chronic hepatitis B. She was asymptomatic; however, a solitary tumor in the left lobe was incidentally detected. After left hepatic lobectomy was performed, a diagnosis of non-Hodgkin's lymphoma was made. No tumor was found except in the liver. Immunohistochemical stains for hepatitis B surface and core antigens were positive in hepatocytes; however, both were negative in the tumor tissue. The patient received no chemotherapy and the tumor relapsed. After chemotherapy, the tumor disappeared. However, exacerbation of hepatitis occurred after the fourth chemotherapy. The patient was followed up without chemotherapy, and she remains in apparent remission. Chemotherapy is effective against primary hepatic lymphoma and, if possible, patients with this disorder should be treated with chemotherapy postoperatively.

Primary hepatic lymphoma is a rare disorder and the clinical behavior remains unknown. We report a patient with primary hepatic lymphoma who had chronic hepatitis B. She was asymptomatic; however, a solitary tumor in the left lobe was incidentally detected. After left hepatic lobectomy was performed, a diagnosis of non-Hodgkin's lymphoma was made. No tumor was found except in the liver. Immunohistochemical stains for hepatitis B surface and core antigens were positive in hepatocytes; however, both were negative in the tumor tissue. The patient received no chemotherapy and the tumor relapsed. After chemotherapy, the tumor disappeared. However, exacerbation of hepatitis occurred after the fourth chemotherapy. The patient was followed up without chemotherapy, and she remains in apparent remission. Chemotherapy is effective against primary hepatic lymphoma and, if possible, patients with this disorder should be treated with chemotherapy postoperatively.