Leukemia - acute
General

Author: Syed Zaidi, M.D. (see Authors page)

Revised: 30 August 2017, last major update December 2011

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Acute leukemia general [title]

Cite this page: Zaidi, S. Leukemia - acute - General. PathologyOutlines.com website. http://pathologyoutlines.com/topic/leukemiaacuteleukemiageneral.html. Accessed November 22nd, 2017.
Definition / general
  • "Acute" because cells are immature (usually blasts) compared to mature hematopoietic cells in chronic leukemias
  • Acute leukemias also tend to progress rapidly without treatment, compared to indolent behavior of chronic leukemias
Clinical features
  • Ionizing radiation is only definite environmental risk factor (Environ Health Perspect 2007;115:138)
  • Course of disease not affected by pregnancy (Cancer 2005;104:110)
  • Initial diagnosis usually based on blood counts and blood smear
  • Bone marrow examination (biopsy and smears) is necessary to confirm diagnosis and to obtain material for special studies
  • Bone marrow biopsy is essential to assess cellularity extent of involvement and to monitor posttreatment changes
  • Cytogenetics and molecular studies are required to classify and provide prognostic information
  • Before making a diagnosis, review clinical information, all pathology material and special studies
  • Immunostains should be ordered in panels (with multiple antigens) since aberrant antigen expression is common
  • Common lymphoid immunostains: TdT, T cell - CD2, CD3 (cytoplasmic), CD5, CD7; B cell - HLA-DR, CD10, CD19, CD22, CD79a (cytoplasmic), PAX5, CD20 (tissue sections)
  • Common myeloid immunostains: CD13, CD14, CD15, CD33, CD36, CD61, CD64

    Posttreatment:
  • Initially hypocellular with necrosis, proteinaceous debris, dilated sinuses and increased reticulin
  • Regeneration begins after 1 - 2 weeks
  • May be difficult to differentiate residual disease (tumor cells in no specific locations) from regenerating marrow (promyelocytes are perivascular and endosteal), particularly in acute promyelocytic leukemia
  • May have granulomas associated with microorganisms
Microscopic (histologic) description
  • Bone marrow usually markedly hypercellular with replacement of normal cells by myeloblasts
  • Myelofibrosis relatively common
  • Marrow is rarely hypocellular resembling aplastic anemia but most cells are blasts