Lymph node blast crisis in chronic myeloid leukemia mimicking T-immunoblastic lymphoma.
BACKGROUND
Chronic myeloid leukemia arises from a somatic mutation in a pluripotent stem cell. It generally terminates with a blastic crisis (BC). One third of BC are lymphoid, and most have a pre-B phenotype. Few cases of T-lymphoid BC have been reported. Here we describe a lymph node blast crisis mimicking T-immunoblastic lymphoma.


METHODS
Bone marrow and lymph nodes were histologically examined by standard methods and by an immunoperoxidase technique. Cytogenetic studies were also performed on lymph node and blood cells. Analysis of T-cell receptor genes and BCR rearrangements were performed on DNA extracted from both frozen bone marrow and lymph-node cells.


RESULTS
Lymph-node histology showed an infiltration by large lymphoid blasts, consistent with a diagnosis of immunoblastic lymphoma. Blast cells were CD2, CD7, TDT positive, and negative for myeloid and mature lymphoid antigens. The Ph1 chromosome was found in both bone marrow and lymph-node cells. BCR rearrangement was found in the DNA from both bone marrow and lymph-node cells. TCR genes were not rearranged.


CONCLUSIONS
The present study provides strong evidence that the lymph-node blast crisis of CML can assume the morphological appearance of immunoblastic lymphoma and may retain the immunological phenotype and genetic features of early T cells with BCR rearrangements.
Leone
G
G
Istituti di Semeiotica Medica, Università Cattolica del S. Cuore, Roma, Italy.
La Rocca
L M
LM
Teofili
L
L
De Candia
E
E
Landolfi
R
R
Sica
S
S
Zini
G
G
Zollino
M
M
Tabilio
A
A
D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D001752:Blast Crisis / Q000175:diagnosis* / Q000473:pathology; D001853:Bone Marrow / Q000473:pathology; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D016130:Immunophenotyping; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D016400:Lymphoma, Large-Cell, Immunoblastic / Q000175:diagnosis*; D016399:Lymphoma, T-Cell / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D016044:Fusion Proteins, bcr-abl