Fifteen cases of large-cell lymphoma, diagnosed as centroblastic (5), B-immunoblastic (5) or true histiocytic (5). lymphoma and one case of malignant histiocytosis were studied with monoclonal antibodies. Each diagnosis was based on morphological as well as marker studies. A panel of monoclonal and heterologous antibodies against T lymphocyte differentiation antigens (Leul, Leu2a, Leu3a, OKT4, ...

Seventy-one previously untreated patients with non-Hodgkin lymphomas were studied with several readilyvailable tests of immune function: number of peripheral blood lymphocytes, serum immunoglobulins, and delayed hypersensitivity to six recall antigens. The results were correlated to histology (Rappaport classification), stage (Ann Arbor classification), the presence of symptoms, and survival. A...

There are few disease entities so confusing as those related to the histiomonocytic cells and their malignant proliferations, defined either as Malignant Histiocytosis or histiocytic lymphoma. Both terms have been considered synonymous and employed indifferently by most Authors, although certain differences in the clinical manifestations have sometimes been outlined. The term “malignant-histioc...

BACKGROUND Histiocytic sarcoma is a rare histiocytic neoplasm of unknown etiology that constitutes less than 1% of hematologic malignancies. A few cases of histiocytic sarcoma harboring the BRAF V600E mutation have been reported, but this finding has not been confirmed in all studies. CASE PRESENTATION We report the case of a 63-year-old white woman with a history of splenic marginal zone lym...

Tumor necrosis factor-α-inducible protein-2 (TNFAIP2) is a protein upregulated in cultured cells treated with tumor necrosis factor α (TNF), but its expression in normal and neoplastic tissues remains largely unknown. Here, we use standard immunohistochemical techniques to demonstrate that TNFAIP2 is normally expressed by follicular dendritic cells, interdigitating dendritic cells, and macropha...

Transdifferentiation of B cell lymphoma of germinal center cell origin to histiocytic sarcoma has recently been described but is a rare occurrence. The cause for loss of B cell differentiation in these lymphomas is unknown. We investigated whether somatic hypermutation of the PAX-5 gene, a transcription factor that is important for maintaining B cell identity and is frequently mutated in B cell...

Malignant histiocytosis (MH) and true histiocytic lymphoma (THL) are hematopoietic malignancies of the mononuclear phagocytic system distinguished from each other by clinical presentation and presumed cell of origin. THL present as a localized mass derived from the fixed tissue histiocyte which may or may not disseminate. MH originates from the circulating monocyte or tissue macrophage and is c...