Unusual karyotypic changes and B cell involvement in a case of lymph node
blast crisis of chronic myelogenous leukemia
DE Hogge, S Misawa, JR Testa, RD Leavitt, A Pollak and CA Schiffer
A patient with Philadelphia chromosome (Ph1) positive chronic myelogenous
leukemia (CML) entered a blast crisis localized to lymph nodes. On light
microscopy, by morphology and histochemical staining, the blasts were
undifferentiated. In spite of terminal deoxynucleotidyl transferase
positivity, some of the lymph node cells expressed a myeloid
differentiation antigen, OKM1, and were peroxidase positive by transmission
electron microscopy (TEM). However, the majority of cells were peroxidase
negative on TEM and expressed OKT-10, a marker found on both primitive
myeloid and lymphoid cells. Cultures of lymph node cells stimulated with
Epstein-Barr virus or lipopolysaccharide (LPS) revealed the Ph1, indicating
B cell involvement in the CML. T cells from cultures stimulated with
L4-phytohemagglutinin and T cell growth factor were negative for the Ph1.
In unstimulated lymph node cells, the uncomplicated Ph1 could not be
demonstrated; instead, a unique complex karyotype involving a masked Ph1
was identified in these and the LPS cultures. This karyotype was not found
in bone marrow (BM) metaphase cells. Instead, BM cells showed either the
simple Ph1 or the Ph1 with a rearrangement involving chromosomes 13 and 20.
The patient had transient responses to three chemotherapy regimens, two of
which were designed to treat acute lymphocytic leukemia, but he died 8
months after disease acceleration without BM blast crisis. These findings
are compatible with an extramedullary blast crisis originating in a
primitive cell with both myeloid and lymphoid characteristics.
Volume 64,
Issue 1,
pp. 123-130,
07/01/1984
Copyright © 1984 by The American Society of Hematology
