Follicular origin of a subset of CD5+ diffuse large B-cell lymphomas

• Published in: American journal of clinical pathology Vol. 124; no. 2; pp. 182 - 190
• Main Authors: MANAZZA, Andrea D, BONELLO, Lisa, PALESTRO, Giorgio, CHIARLE, Roberto, PAGANO, Marco, CHIUSA, Luigi, NOVERO, Domenico, STACCHINI, Alessandra, MARTINI, Giuseppe, VITOLO, Umberto, TARELLA, Corrado, INGHIRAMI, Giorgio
• Format: Journal Article
• Language: English
• Published: Chicago, IL American Society of Clinical Pathologists 01.08.2005
• Subjects: Aged; Biological and medical sciences; Biomarkers, Tumor - metabolism; CD5 Antigens - metabolism; DNA Mutational Analysis; Female; Gene Rearrangement, B-Lymphocyte, Heavy Chain; Hematologic and hematopoietic diseases; Humans; Immunohistochemistry; Immunophenotyping; Investigative techniques, diagnostic techniques (general aspects); Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Lymphoma, B-Cell - pathology; Lymphoma, Follicular - pathology; Lymphoma, Large B-Cell, Diffuse - pathology; Male; Medical sciences; Middle Aged; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Prognosis; Diffuse; Origin; Anatomic pathology; Histogenesis; CD5; Lymphoproliferative syndrome; Follicular lymphoma; Malignant hemopathy; Large cell lymphoma; Non Hodgkin lymphoma; Diffuse large B-cell lymphoma
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1309/8ex5b9jfhpek82bu

Most follicular lymphomas (FLs) have a phenotype consistent with the origin from CD5-, CD10+, bcl-6+ follicular center cells and can progress to diffuse large B-cell lymphoma (DLBCL). CD5 is expressed in about 10% of DLBCLs, showing prognostic value, whereas expression is rare in FL. We present 6 cases with coexisting features of CD5+ FL and CD5+ DLBCL, supporting a follicular origin for some CD5+ DLBCLs. The follicular areas showed a meshwork of CD21+ follicular dendritic cells that were lacking in the DLBCL areas. All cases showed a clonal CD19+, CD20+, CD5+, and CD10+ population in both follicular and diffuse areas. Molecularly, 4 of 6 cases demonstrated immunoglobulin heavy chain rearrangements and 1 case, a bcl-2/immunoglobulin heavy chain gene rearrangement. Somatic hypermutations were high in all 4 cases, in keeping with their germinal center origin. Four of five patients died of disease within 42 months, consistent with the proposed prognostic value of CD5 expression in DLBCL. Our data describe an aggressive variant of CD5+ FL suggesting the follicular origin of some CD5+ DLBCLs.