Clinical and morphological features were mostly consistent with follicular lymphoma, with a few features more often seen in marginal zone lymphomas (leukemic presentation, no CD10 in circulating cells, interstitial location of tumor cells in bone marrow); therefore, these cases were finally classified as follicular lymphoma grade I.
Including DNA cell cycle analysis in the FC lymphoma assessment panel may be of diagnostic value in differentiating between CD10+ DLBCL and FL when adequate biopsy is unavailable.
BCL2-break-positive cases had a tendency to occur in the head and neck and showed the classical phenotype of nodal follicular lymphoma (CD10+, BCL6+, BCL2+, STMN+) compared with BCL2-break-negative PCFCLs.Del 1p36 was observed in 1 PCFCL.
CD10 expression was significantly reduced in BCL2-breakpoint-negative FLs of all stages and MUM1 and Ki67 expression were significantly increased in BCL2-break-negative early-stage FLs.
Both cases of FL were positive for CD10 and B-cell lymphoma 2 (BCL-2), and immunoglobulin heavy locus (IgH)/B-cell lymphoma 2 rearrangement was observed by fluorescence in situ hybridization.
Both cases showed near total effacement of the lymph node architecture by grade 1 FL (CD10+ and BCL2+) with accompanying in situ MCL component (CD5+ and cyclin D1+) surrounding neoplastic follicles.
This study aimed to determine the correlations of 7 histopathologic prognostic indicators of follicular lymphoma (follicular lymphoma grade, CD10 expression, Bcl-2 expression, IGH/BCL2 fusion, diffuse area, fibrosis, and marginal zone differentiation) with progression-free survival, overall survival, and follicular lymphoma histologic grade in 255 follicular lymphoma patients who were treated with rituximab-containing therapy.
STMN1 (stathmin) was shown to be helpful in diagnosing bcl-2-negative and/or CD10-negative follicular lymphomas, and in their distinction from marginal zone B-cell lymphoma.
Comparison of the gene expression profiles of NMZL and FL showed enriched expression of CHIT1, TGFB1, and TACI in NMZL, and BCL6, LMO2, and CD10 in FL.
Follicular lymphomas in the other group lacked IGH-BCL2 and Bcl-2 expression, were often of WHO grade 3 and were often CD10-negative, similar to the minority of follicular lymphomas previously described that are Bcl-2-negative and are often encountered at other extranodal sites.
These findings were confirmed by immunohistochemistry in an independent validation series of 84 FLs, in which 32% of t(14;18)-negative FLs showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate.
Splenic FL cases could be divided into 2 main variants: one was similar to classic FL with t(14;18) and CD10 expression, whereas the other was characterized by a higher proliferation index and histologic grade, and was more frequently diagnosed as a disease restricted to the spleen.
We have therefore investigated the immune response in FL using real-time polymerase chain reaction (PCR) to measure expression levels of 35 candidate Indicator genes, selected from microarray studies, to polyA cDNAs prepared from 60 archived human frozen lymph nodes, in parallel with immunohistochemical analysis for CD3, CD4, CD7, CD8, CD10, CD20, CD21, and CD68.
All dual-translocation FLs were CD10+/BCL6+/BCL2+/MUM1-, and the DLBCLs demonstrated "activated" germinal center (CD10+/BCL6+/MUM1+) and non-germinal center (CD10-/BCL6+/MUM1+) phenotypes.
In many cases immunophenotyping, particularly analysis of reactivity for CD5 and CD10, is an important adjunct to morphology that usually distinguishes MCL from follicular lymphoma; the former is CD5(+)/CD10(-), whereas follicular lymphoma is the reverse.
The analysis suggests that MUM1 expression dichotomises FL into low-grade FL of CD10+/Bcl-6+/MUM1-/Ki-67low phenotype, and high-grade FL of CD10+/- /Bcl-6+/weak/MUM1+/ Ki-67high phenotype.
The analysis suggests that MUM1 expression dichotomises FL into low-grade FL of CD10+/Bcl-6+/MUM1-/Ki-67low phenotype, and high-grade FL of CD10+/- /Bcl-6+/weak/MUM1+/ Ki-67high phenotype.