Medical brain notes 15

  Leukocytosis Leukocytosis is characterized by an elevated white blood cell count. It has the fol-lowing features: •           Increased neutrophils (neutrophilia) Increased bone marrow production is seen with acute inflammation associated with pyogenic bacterial infection or tissue necrosis Increased release from bone marrow storage pool may be caused by corti­ costeroids, stress, or endotoxin Increased bands (“left shift”) noted in peripheral circulation Reactive changes include Döhle bodies (aggregates of rough endoplasmic reticulum), toxic granulations (prominent granules), and cytoplasmic vacuoles of neutrophils •           Increased eosinophils (eosinophilia) occurs with allergies and asthma (type I hypersensitivity reaction), parasites, drugs (especially in hospitals), and certain skin diseases and cancers (adenocarcinomas, Hodgkin disease). •        ...

  LYMPHOID NEOPLASMS Lymphoid neoplasia  is grouped according to the 2008 WHO classification as follows   (note that B and T lymphoblastic lymphoma/leukemia is grouped by the WHO with myeloid neoplasia):   •           Mature B-cell neoplasms   •           Mature T-cell and NK-cell neoplasms   •           Hodgkin lymphoma   •           Histiocytic and dendritic cell neoplasms   •           Posttransplantation lymphoproliferative disorders

  MATURE B-CELL NEOPLASMS Chronic lymphocytic leukemia (CLL)  and  small lymphocytic lymphoma (SLL)  are very   similar; they both represent an abnormal proliferation of B cells. Patients who pres-ent with  lymph node findings  are classified as having SLL. Patients who present with  blood findings  are classified as having CLL; 50% of CLL patients also have lymph node involvement.   •           CLL is the most indolent of all of the leukemias.   •           Mean age at time of diagnosis is age 60.   •           The malignant cells are nonfunctional, so patients develop hypogammaglobu-linemia, leading to an increased risk of infections. •           CLL is associated with warm autoimmune hemolytic anemia (AIHA) (10% of cases), which will cause spherocy...

  PERIPHERAL T-CELL AND NATURAL KILLER CELL NEOPLASMS Peripheral T-cell lymphoma, unspecified is a “wastebasket” diagnostic category. Adult T-cell leukemia/lymphoma (ATLL) is a malignant T-cell disorder (CD4-T cells) due to HTLV-1 infection. It is often seen in Japan and the Caribbean. Clinical symp-toms include skin lesions, hypercalcemia, enlarged lymph nodes, heptomegaly, and splenomegaly. Microscopically, characteristic hyperlobated “4-leaf clover” lympho-cytes can be found in the peripheral blood. Mycosis fungoides is a malignant T-cell disorder (CD4+ cells) that has a better prognosis than ATLL. It can present with a generalized pruritic erythematous rash (no hypercalcemia), which develops as a sequence of skin changes: inflammatory eczematous stage → plaque stage → tumor nodule stage Microscopically, atypical PAS-positive lymphocytes are present in the epidermis (epidermotropism); aggregates of these cells are called Pautrier microabscesses. If there is erythroderma and cere...

  HODGKIN LYMPHOMA   Hodgkin lymphoma has some characteristics that are different from non-Hodgkin lymphoma. •           May present similar to infection (with fever) •           Spread is contiguous to adjacent node groups •           No leukemic state •           Extranodal spread is uncommon The malignant cells are the diagnostic Reed-Sternberg cells; these malignant cells are intermixed with reactive inflammatory cells. The Reed-Sternberg cell is a large malignant tumor cell that has a bilobed nucleus with a prominent large inclusion-like nucleolus in each lobe. Hodgkin lymphoma classification:   •           Lymphocyte-rich  type (rare): composed primarily of reactive lymphocytes;   associated with Epstein-Barr virus (40% of cases) ...