Table of Contents
Definition / general | Clinical features | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Immunohistochemistry | Molecular / cytogenetics descriptionCite this page: Luca DC. PTLD-monomorphic. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lymphomanonBmonomorphic.html. Accessed January 22nd, 2021.
Definition / general
- Fulfill the criteria for one of the B cell or NK/T cell neoplasms recognized in the immunocompetent host (WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, 4th Edition, Lyon 2008)
- Exception: small B cell lymphoid neoplasms (follicular lymphoma, MALT) not designated as a posttransplantation lymphoproliferative disorder (PTLD)
- Monomorphic PTLD (M-PTLD) should be diagnosed as a PTLD and further subclassified based on the WHO lymphoma classification (e.g., posttransplant lymphoproliferative disorder, diffuse large B cell lymphoma type)
- Monoclonal transformed B lymphocytic or plasmacytic proliferations that fulfill the criteria for a diffuse large B cell lymphoma, less often a Burkitt lymphoma or a plasma cell neoplasm (Haematologica 2011;96:1067)
Clinical features
- Similar to B cell lymphomas and plasma cell neoplasms in immunocompetent individuals
Case reports
- 11 year old boy and 44 year old man with Burkitt-like PTLD (Pathol Oncol Res 2002;8:105)
- 38 year old woman with M-PTLD of ovary (J Med Case Reports 2010;4:184)
- 47 year old man with M-PTLD of tongue (Diagn Pathol 2007;2:49)
Microscopic (histologic) description
- Fulfill criteria for conventional diffuse large B cell lymphoma, Burkitt lymphoma, myeloma or plasmacytoma
- Lack the full range of maturation seen in polymorphic PTLD
- Significant pleomorphism may be present; monomorphic does not mean complete cellular monotony
Microscopic (histologic) images
Immunohistochemistry
- Nonplasmacytic lesions: CD19+, CD20+, CD79a+, PAX5+, monotypic Ig (often γ or α heavy chain), CD30+ (many)
- Most M-PTLD are of nongerminal center type, based on immunohistochemistry
- EBV+ cases: CD10-, bcl6+/-, IRF4 / MUM1 +, CD138-/+ (late / post GC phenotype)
- EBV- cases: CD10+/-, BCL6+, IRF4 / MUM1-, CD138- (GC phenotype)
Molecular / cytogenetics description
- Clonal Ig gene rearrangements in virtually all cases
- EBV genomes in clonal episomal form
- Somatic mutations of IGV
- RAS, TP53, MYC, bcl6 anomalies
- Cytogenetic abnormalities: 1q11-q21, 8q24.1, 3q27, 16p13, 14q32, 11q23-24, +9, +11, +7, +X, +2, +12
- EBV PTLD: often lack expression of CDKN2A