malignant histiocytosis


ma·lig·nant his·ti·o·cy·to·sis

a rapidly fatal form of lymphoma, characterized by fever, jaundice, pancytopenia, and enlargement of the liver, spleen, and lymph nodes; the affected organs show focal necrosis and hemorrhage, with proliferation of histiocytes and phagocytosis of red blood cells.

malignant histiocytosis

A systemic proliferation of large atypical histiocytes that actively phagocytose RBCs, WBCs, platelets and precursors in lymph nodes, splenic red pulp, bone marrow, skin, GI tract, kidneys, adrenal glands and lungs; it is accompanied by bone marrow necrosis, pancytopenia, hepatitis and coagulopathy.
Clinical findings
Aggressive, generalised lymphadenopathy, hepatosplenomegaly, pulmonary involvement and pancytopenia; often fatal; fever, weakness, weight loss, diaphoresis, chest and back pain, rash, subcutaneous tumour nodules, pancytopenia, increased bilirubin followed by jaundice; it may cause rapid deterioration.
 
Demographics
Male:female ratio, 2–3:1; any age.
Associations
While idiopathic, malignant histiocytosis is associated with ALL and AML, post-renal transplantation immunosuppressive therapy and EBV viraemia, as well as lethal midline granuloma.
 
DiffDx
Virus-associated haemophagocytic syndrome, reactive histiocytosis of T-cell proliferation, AML-FAB M5, hairy cell leukaemia, “histiocytic” and Hodgkin lymphomas, melanoma, anaplastic/large cell carcinoma, infectious mononucleosis, sinus histiocytosis with massive lymphadenopathy, familial haemophagocytic reticulosis, Langerhans’ cell histiocytosis.
Management
Multidrug regimen (e.g., vincristine, cyclophosphamide, doxorubicin, prednisone).

malignant histiocytosis

Hematology A term that has been used for 3 different conditions 1. Malignant lymphoma. See Lymphoma.2. 'Regressing atypical histiocytosis' An indolent pre-histiocytic lymphoma accompanied by chromosome defects Clinical Vague heterogenous clinical picture; peak onset in the 3rd decade, commonly with extranodal involvement of the GI tract, skin, BM Prognosis Good.3. Malignant histiocytosis of Robb-Smith A rapidly fatal disease associated with aggressive proliferation of atypical histiocytes and precursors in lymph nodes, splenic red pulp, BM, skin, GI tract, kidneys, adrenal glands and lungs; although idiopathic, MH is associated with ALL and AML, post-renal transplantation immunosuppressive therapy and EBV viremia, lethal midline granuloma Clinical ♂:♀ ratio, 2-3:1; at any age; fever, weakness, weight loss, diaphoresis, chest and back pain, rash, lymphadenopathy, hepatosplenomegaly, subcutaneous tumor nodules, pancytopenia, ↑ BR followed by jaundice, it may cause rapid deterioration DiffDx AML-FAB M5, hairy cell leukemia, 'histiocytic', and Hodgkin's lymphomas, melanoma, anaplastic or 'large cell' carcinoma, virus-associated hemophagocytic syndrome, infectious mononucleosis, sinus histiocytosis with massive lymphadenopathy, familial hemophagocytic reticulosis, Langerhans' cell histiocytosis; may cause lethal midline granuloma Treatment Multidrug regimen–eg, vincristine, cyclophosphamide, doxorubicin, prednisone. See Histiocytosis.

ma·lig·nant his·ti·o·cy·to·sis

(mă-lig'nănt his'tē-ō-sī-tō'sis) A rapidly fatal form of lymphoma, characterized by fever, jaundice, pancytopenia, and enlargement of the liver, spleen, and lymph nodes; the affected organs show focal necrosis and hemorrhage, with proliferation of histiocytes and phagocytosis of red blood cells.