histiocytic medullary reticulosis

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reticulosis

[rĕ-tik″u-lo´sis]

an abnormal increase in cells derived from or related to the reticuloendothelial cells.

familial histiocytic reticulosis (histiocytic medullary reticulosis) a fatal hereditary disorder marked by anemia, granulocytopenia, thrombocytopenia, phagocytosis of blood cells, diffuse proliferation of histiocytes, and enlargement of the liver, spleen, and lymph nodes.

midline malignant reticulosis lethal midline granuloma thought to be due to lymphoma.

pagetoid reticulosis a solitary skin lesion of long duration and slow growth characterized histologically by large numbers of abnormal mononuclear cells infiltrating the epidermis with an underlying reactive mixed dermal infiltrate.

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).

histiocytic lesion

An aggregate of histiocytes, which may be benign, indeterminant, or malignant in proliferative potential; to reduce confusion, it has been suggested that histiocytoses be subdivided into different categories

Histiocytic lesions-Behavior classification

Benign

• Familial histiocytosis with eosinophilia A chronic disease of infants with recurring bacterial infections, diarrhea, eczema, alopecia, associated with immunodeficiency

• Sinus histiocytosis with massive lymphadenopathy Rosai-Dorfman disease A disease most common in adolescent blacks with massive cervical lymphadenopathy as well as enlargement of extranodal (orbit, skin, bone, salivary gland, testis) lymphoid tissues

• Virus-associated hemophagocytic syndrome A condition induced by viral infections, often accompanied by abnormal liver function tests, coagulation assays and pancytopenia Pathology Histiocyte hyperplasia, hemophagocytosis and replacement of native bone marrow elements

Intermediate

• Histiocytosis X, aka Langerhans' cell histiocytosis, see there.

• Reactive hemophagocytic syndrome, see there.

Malignant

• Histiocytic medullary reticulosis see there.

• Histiocytic proliferations, eg—acute monocytic leukemia (FAB M3), histiocytic lymphoma see there, malignant histiocytosis–see there.

histiocytic medullary reticulosis

A form of malignant histiocytosis marked by anemia; granulocytopenia; enlargement of the spleen, liver, and lymph nodes; and phagocytosis of red blood cells.