title: State of the art in myeloid sarcoma.
abstract: BACKGROUND
  Myeloid sarcomas are extramedullary lesions composed of myeloid lineage blasts that typically form tumorous masses and may precede, follow, or occur in the absence of systemic acute myeloid leukemia. They most commonly involve the skin and soft tissues, lymph nodes, and gastrointestinal tract and are particularly challenging to diagnose in patients without an antecedent history of acute myeloid leukemia.
  
  
  METHODS
  We conducted a search of the English language medical literature for recent studies of interest to individuals involved in the diagnosis of myeloid sarcoma.
  
  
  RESULTS
  The differential diagnosis includes non-Hodgkin lymphoma, blastic plasmacytoid dendritic cell neoplasm, histiocytic sarcoma, melanoma, carcinoma, and (in children) small round blue cell tumors. The sensitivity and specificity of immunohistochemical markers must be considered when evaluating a suspected case of myeloid sarcoma. A high percentage of tested cases have cytogenetic abnormalities.
  
  
  CONCLUSIONS
  A minimal panel of immunohistochemical markers should include anti-CD43 or anti-lysozyme as a lack of immunoreactivity for either of these sensitive markers would be inconsistent with a diagnosis of myeloid sarcoma. Use of more specific markers of myeloid disease, such as CD33, myeloperoxidase, CD34 and CD117 is necessary to establish the diagnosis. Other antibodies may be added depending on the differential diagnosis. Identification of acute myeloid leukemia-associated genetic lesions may be helpful in arriving at the correct diagnosis.
authors: Department of Pathology and Immunology, Washington University, School of Medicine, St Louis, MO 63110, USA.
authors: J M
authors: JM
authors: Klco
authors: J S
authors: JS
authors: Welch
authors: T T
authors: TT
authors: Nguyen
authors: M Y
authors: MY
authors: Hurley
authors: F H
authors: FH
authors: Kreisel
authors: A
authors: A
authors: Hassan
authors: A C
authors: AC
authors: Lind
authors: J L
authors: JL
authors: Frater
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D002869:Chromosome Aberrations; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D023981:Sarcoma, Myeloid / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism*; D063268:Sialic Acid Binding Ig-like Lectin 3
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D015214:Antigens, Differentiation, Myelomonocytic; D014408:Biomarkers, Tumor; C571163:CD33 protein, human; D063268:Sialic Acid Binding Ig-like Lectin 3; D019009:Proto-Oncogene Proteins c-kit