Plasmablastic lymphoma of the stomach in an HIV-negative patient.

Plasmablastic lymphoma (PBL) is a rare B-cell neoplasm with an aggressive clinical behavior that predominantly occurs in the oral cavity of human immunodeficiency virus (HIV)-positive patients. However, it has recently been recognized that PBLs can also affect individuals without HIV infection, and suggested that these neoplasms show different clinicopathological characteristics between HIV-positive and -negative patients. Herein we describe a case of gastric PBL in a female HIV-negative patient. The tumor was composed of a diffuse and cohesive proliferation of large neoplastic cells, which resembled immunoblasts or plasmablasts with a starry sky appearance. Immunophenotypically, the neoplastic cells were diffusely positive for CD138, MUM1, IgM, and BOB-1, and negative for CK, LCA, CD3, CD20, CD79a, Pax5, kappa, lambda, CD30, ALK, S-100, HMB-45, MPO, and HHV-8. The MIB-1 index was nearly 100%. Epstein-Barr virus-encoded RNA in situ hybridization was negative. A monoclonal immunoglobulin heavy chain gene rearrangement was detected in polymerase chain reaction (PCR) and heteroduplex analyses. A combination of PCR-based analysis of immunoglobulin gene rearrangement and immunohistochemistry can be useful to substantiate the diagnosis by utilizing routine paraffin-embedded tissue sections, because PBL in the setting of extra-oral localization and immunocompetence is a diagnostic challenge, given its rarity, morphology, and absence of CD20 expression.

Unrelated bone marrow transplantation induced long-term remission in a patient with life-threatening Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis.

We present a case of life-threatening Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) with severe hepatitis that was successfully treated by allogeneic stem cell transplantation from an unrelated donor. A 26-year-old woman was admitted to hospital with a high fever and liver dysfunction. Laboratory tests, including bone marrow aspiration, revealed severe HLH that occurred after EBV infection. High-dose methylprednisolone and etoposide therapy did not control the disease. We could control the HLH, but the EBV viremia continued following the CHOPE (cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide) chemotherapy regimen. Therefore, the patient underwent allogeneic bone marrow transplantation from an HLA-matched, unrelated donor. The patient has remained in good condition without disease recurrence for 2 years after bone marrow transplantation. Although there is no consensus regarding allogeneic stem cell transplantation for EBV-HLH, it is the treatment of choice for aggressive EBV-HLH when the patient is refractory to intensive chemotherapy.

[Acute leukemia in two brothers].

A 42-year-old man was diagnosed as having refractory anemia in May, 2001. He developed overt leukemia and received allogeneic bone marrow transplantation (BMT). His younger brother, a 40-year-old man, was diagnosed as having acute leukemia with trilineage myelodysplasia in November, 2001. Although he was treated with conventional chemotherapy, he failed to achieve complete remission. He also received allogeneic BMT. We suggest that environmental factors in addition to a genetic defect in the pluripotent hematopoietic stem cells may be associated with the occurrence of this familial leukemia.