Complex MLL rearrangement in non‐infiltrated bone marrow in an infant with stage II precursor B‐lymphoblastic lymphoma. (28th April 2014)

• Record Type: Journal Article
• Authors: Ahlmann, Martina; Meyer, Claus; Marschalek, Rolf; Burkhardt, Birgit; Koehler, Gabriele; Klapper, Wolfram; Juergens, Heribert; Rossig, Claudia
• Is Part Of: European journal of haematology. Volume 93:Number 4(2014:Oct.)
• Page Start: 349
• Page End: 353
• Publication Date: 2014-04-28
• Subjects: Hematology -- Periodicals; Blood -- Diseases -- Periodicals; Blood -- Periodicals; 616.15005
• DOI: 10.1111/ejh.12314
• Languages: English
• ISSNs: 0902-4441

Abstract

<abstract abstract-type="main" id="ejh12314-abs-0001"> <title>Abstract</title> <sec id="ejh12314-sec-0001" sec-type="section"> <title>Purpose</title> <p>Precursor B‐lymphoblastic lymphoma cells are indistinguishable by morphology, and immune phenotype from lymphoblasts in acute leukemia which in infancy is associated with <italic>MLL</italic> rearrangements and a poor prognosis. The role of <italic>MLL</italic> gene deregulation in rare cases of isolated lymphoblastic lymphoma in infants is obscure. We report the case of a 10‐month‐old child who presented with a cutaneous nodule on the left foot. Histological diagnosis was precursor B‐lymphoblastic lymphoma. The young age of the patient motivated us to investigate the presence of an <italic>MLL</italic> rearrangement.</p> </sec> <sec id="ejh12314-sec-0002" sec-type="section"> <title>Methods</title> <p>Cytogenetic analysis was performed by fluorescence <italic>in situ</italic> hybridization (FISH), and the genomic fusion partner of <italic>MLL</italic> was identified by long‐distance inverse (LDI‐)PCR and confirmed by direct PCR.</p> </sec> <sec id="ejh12314-sec-0003" sec-type="section"> <title>Results</title> <p>Fluorescence <italic>in situ</italic> hybridization screening of paraffin‐embedded formalin‐fixed tissue indeed revealed the presence of an <italic>MLL</italic> rearrangement. The genomic fusion partner was identified as <italic>AF10</italic> by DNA sequencing of the <italic>MLL</italic> breakpoint region. The <italic>MLL‐AF10</italic> fusion gene was further detected in cytologically normal pretreated bone marrow. Treatment was started with standard four‐drug induction chemotherapy. Because of the unfavorable outcome associated with <italic>MLL</italic> rearrangements in infant leukemia, we intensified postremission treatment according to the Interfant‐06 study protocol. The child is in continuous first remission 36 months after diagnosis.</p> </sec> <sec id="ejh12314-sec-0004" sec-type="section"> <title>Conclusion</title> <p>This is the first report of submicroscopic bone marrow involvement in <italic>MLL</italic>‐rearranged isolated cutaneous B‐cell precursor lymphoma in an infant. To prospectively address the role of <italic>MLL</italic> rearrangements in extramedullary B‐lymphoblastic malignancies in infants, we suggest to assess both tumors and non‐infiltrated bone marrow for the presence of this genetic abnormality.</p> </sec> </abstract>