Polymorphic PTLD

Lymphoma and plasma cell neoplasms
Posttransplantation lymphoproliferative disorders (PTLD)
Polymorphic PTLD

Author: Dragos Luca, M.D. (see Authors page)

Revised: 17 March 2017, last major update September 2011

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PubMed Search: Polymorphic PTLD

Table of Contents

Cite this page: Polymorphic PTLD. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphomanonBpolymorphicB.html. Accessed July 28th, 2017.

Definition / general

Morphologically polymorphic lesions composed of immunoblasts, plasma cells and small and intermediate sized lymphoid cells that efface the architecture of lymph nodes or form destructive extranodal masses and that do not fulfil the criteria for any of the recognized types of lymphoma described in immunocompetent hosts (WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, 4th Edition, Lyon 2008)
P-PTLD: polymorphic versus M-PTLD: monomorphic

Clinical features

Variable frequency: 20 - 80% of all PTLD
Most common pediatric PTLD
May regress after reduction in immunosuppression or may progress to lymphoma

Microscopic (histologic) description

Architectural effacement but full range of B cell maturation from immunoblasts to plasma cells and variable sized lymphocytes
May have geographic necrosis, HRS-like cells, numerous mitoses
Some may have monomorphic appearing areas - may suggest a continuous spectrum between P and M-PTLD
May have bone marrow lymphoid aggregates of unknown significance (P-PTLD > M-PTLD; children > adults), not always EBV positive

Microscopic (histologic) images

Images hosted on other servers:

Various images

Immunohistochemistry

B cells with (~50%, also by flow cytometry) or without light chain restriction and heterogeneous T cells
Light chain restriction may be focal or different clonal populations may be present simultaneously
RS-like cells (when present): CD30+, CD20+ but CD15-
EBV (EBER) positive
Ki67 may be high

Molecular / cytogenetics description

Clonally rearranged Ig genes but clones less prominent than M-PTLD
EBV terminal repeat analysis - most sensitive method for clonal populations in EBV+ cases
Tumors at different sites may be clonally distinct
75% of P-PTLD have Ig Variable mutations; no significant T cell clones
CGH: some recurrent abnormalities also seen in M-PTLD
May have BCL6 somatic hypermutations