Bone marrow neoplastic

Bone marrow - neoplastic myeloid

AML with recurrent genetic abnormalities

AML with t(9;11)(p22;q23); KMT2A::MLLT3



Last author update: 1 February 2013
Last staff update: 28 April 2023

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PubMed Search: Acute myeloid leukemia with t(9;11)(p22;q23)

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Cite this page: Mihova D. AML with t(9;11)(p22;q23); KMT2A::MLLT3 . PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/leukemiaaml11q23.html. Accessed March 19th, 2024.
Definition / general
Clinical features
  • Symptoms: DIC, extramedullary myeloid sarcoma and tissue infiltration (gingiva, skin)
  • Translocations occur in AML (intermediate prognosis) and ALL (poor prognosis) (Blood Cells Mol Dis 2008;40:192)
  • Prognosis may be superior to other AML with 11q23 translocations
  • MLL partial tandem duplication AML: prognosis varies from poor to similar to other AML (Br J Haematol 2006;135:438, Blood 2007;109:5164)
    • Also present in 93% of normal cord blood samples at low levels (Leuk Res 2006;30:1091)
    • Associated with normal karyotype or trisomy 11
Case reports
Microscopic (histologic) description
  • 20%+ blasts / blast equivalents (monoblasts / monocytes) in peripheral blood or bone marrow, usually myelomonocytic or monocytic (AML M4, M5) and occasionally AML with (M2) or without (M1) maturation
  • Monoblasts are large cells with abundant, moderate to intensively basophilic cytoplasm, pseudopods, azurophilic granules, vacuoles; round nuclei, lacy chromatin and one or more prominent nucleoli
  • Promonocytes have basophilic cytoplasm with granules and occasional large azurophilic granules, vacuoles; irregular and delicately convoluted nuclei
Positive stains
Negative stains
Molecular / cytogenetics description
  • Involves MLL mixed lineage or myeloid / lymphoid leukemia gene, present in both AML and ALL; also called HTRX1, HRX and ALL1
  • FISH is more sensitive than conventional cytogenetics in detecting MLL; may also detect 11q22-25 rearrangements that are MLL negative (Am J Clin Pathol 2004;122:298)

    Variant MLL translocations in AML:
  • > 80 translocations described, most commonly MLLT2(AF4) causing ALL; and MLLT3(AF9) causing AML
  • Mixed phenotype acute leukemia has t(v;11q23)
  • AML-MRC if t(2;11)(p21;q23) or t(11;16)(q23;p13.3)
  • Diagnose as t-AML if history of cytotoxic therapy
  • Other common translocations: 6q27 (MLLT4), 10p12 (MLLT10), 19p13.1 (ELL) and 19p13.3 (MLLT1)
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