Af. Dean et al., HISTOLOGIC, MOLECULAR, AND RADIOLOGIC CHARACTERIZATION OF RESOLVING CEREBRAL POSTTRANSPLANT LYMPHOPROLIFERATIVE DISORDER, Pediatric research, 41(5), 1997, pp. 651-656
Lymphoproliferative disorders (LPDs) are commoner in pediatric versus
adult immunosuppressed transplant recipients, and frequently involve t
he central nervous system. In these circumstances, the justification f
or biopsy is heavily influenced by the likely diagnostic yield. The pr
esent study centers on a 12-y-old renal transplant patient who develop
ed multifocal cerebral LPD and had serial magnetic resonance (MR) exam
inations during the course of her illness from which she has completel
y recovered upon reduction of immunosuppression. She underwent stereot
axic biopsy, which was analyzed by both immunocytochemistry and polyme
rase chain reaction to examine the general question of how to release
the maximum amount of information contained within, as well as to obta
in a tissue diagnosis in this particular case. We show that a combinat
ion of these methods permits identification of the immunophenotype, li
neage, clonality, viral involvement, and origin of abnormal cellular i
nfiltrates. The biopsy also showed a novel histologic pattern of LPD,
comprising numerous benign T cells obscuring a tiny clone of B cells.
The MR examinations documented, for the first time, the differences in
signal that accompany clinical resolution at both biopsied and nonbio
psied sites, showing that the latter may be associated with reduction,
but not elimination, of MR signal abnormality. We conclude: 1) a comb
ination of conventional and polymerase chain reaction analysis offers
the greatest diagnostic yield from stereotaxic biopsies, even when the
available tissue is minimal: 2) a focal polyclonal T cell infiltrate
should prompt further investigation to exclude an underlying B cell le
sion.