T-cell large granular lymphocytic (LGL) leukemia consists of CD4/CD8 and CD4/CD8 LGL populations in association with immune thrombocytopenia, autoimmune neutropenia, and monoclonal B-cell lymphocytosis.

CD3/CD57 T-cell large granular lymphocyte leukemia (T-LGLL) is an indolent neoplasm, exhibiting mostly CD8, less frequently CD4 phenotypes, and T-LGLL consisting of 2 populations with CD8 and CD4 phenotypes is markedly rare. An 87-year-old female was admitted under a diagnosis of immune thrombocytopenia (ITP) with a platelet count of 5.0×10/L and increased number of LGL with unknown etiology.

Gamma heavy chain disease (γ-HCD) as iatrogenic immunodeficiency- associated lymphoproliferative disorder: Possible emergent subtype of rheumatoid arthritis-associated γ-HCD.

Gamma heavy chain disease (γ-HCD) is a rare B-cell neoplasm that produces a truncated immunoglobulin γ-heavy chain lacking the light chain. The clinical features of γ-HCD are heterogeneous, resembling different types of B-cell lymphomas. Although rheumatoid arthritis (RA) is one of the common underlying diseases of γ-HCD, the therapeutic modality for RA has changed greatly in recent years; therefore, γ-HCD as iatrogenic immunodeficiency-associated lymphoproliferative disorder (LPD) should be taken into consideration.

Gamma-heavy chain monoclonal gammopathy with undetermined significance (MGUS).

Gamma-heavy chain disease (γ-HCD) is a rare B-cell tumor producing truncated IgG lacking the light chain. The clinical features of γ-HCD are heterogeneous, similar to lymphoplasmacytic lymphoma, and most patients have generalized and progressive disease. In some γ-HCD patients, autoimmune diseases are associated.

Acute monocytic leukemia diagnosed by flow cytometry includes acute myeloid leukemias with weakly or faintly positive non-specific esterase staining.

A diagnosis of acute monocytic leukemia (AML-M5) based on α-naphthyl butyrate esterase (α-NB) staining has some problems, because AML-M5 leukemic cells often show weak or faint positivity on α-NB staining. In these situations, some cases of AML-M5 tend to be misdiagnosed as AML-M0. Therefore, we evaluated the significance of weak or faint α-NB staining in AML-M5 diagnosed by flow cytometry (FCM).

Colonal monomorphic epitheliotropic intestinal T-cell lymphoma with novel phenotype of cytoplasmic CD3 expression.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a new clinical entity that was reclassified from enteropathy-associated T-cell lymphoma in the 2016 WHO classification. An 83-year-old man with fever and diarrhea was referred to our hospital because of free air in the abdominal cavity and wall thickening of the large intestine on CT. Colonofiberscopic examination revealed mucosal edema and multiple ulcers at the sigmoid colon, splenic flexure, and transverse colon.

Analysis of gastrointestinal virus infection in immunocompromised hosts by multiplex virus PCR assay.

Regarding viral infection of intestinal mucosa, there have been only a few studies on limited diseases, targeting a few herpes family viruses. In this study, we analyzed 12 kinds of DNA viruses including 8 species of herpes family viruses in the gastrointestinal mucosa of patients with hematologic malignancies, inflammatory bowel diseases, collagen diseases, or other miscellaneous forms of gastroenteritis using the multiplex virus PCR assay, which we recently developed. The virus PCR assay yielded positive results in 63 of 102 patients; Epstein-Barr virus (EBV) was the most frequently detected, followed by cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, parvovirus B19, and herpes simplex virus type 1.

Composite Lymphoma as Co-occurrence of Advanced Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma Carrying Trisomy 12 and t(14;18) and Peripheral T-cell Lymphoma.

Composite lymphoma is defined as the co-occurrence of two types of lymphoma, comprising 1-4% of lymphomas, and the association of B-cell-type chronic lymphocytic leukemia (B-CLL)/small lymphocytic lymphoma and peripheral T-cell lymphoma (PTCL) is rare. Here, we report a case (77-year-old woman) of advanced B-CLL complicated by newly appearing PTCL. Two years after the onset of B-CLL, CLL cells acquired CD38 antigen expression and the disease entity became CLL/prolymphocytic leukemia.