Phenotype profiling of primary testicular diffuse large B-cell lymphomas.

Area of Science:

• Oncology
• Hematology
• Pathology

Background:

• Primary testicular diffuse large B-cell lymphomas (tDLBCL) are rare and lack comprehensive characterization.
• Understanding tDLBCL phenotype is crucial for diagnosis and treatment strategies.

Purpose of the Study:

• To systematically characterize the phenotype of tDLBCL using multimarker analysis.
• To identify potential prognostic markers and signaling pathway involvement in tDLBCL.

Main Methods:

• Retrospective review of 45 tDLBCL patients diagnosed between 1972 and 2009.
• Tissue microarray construction with immunohistochemistry and fluorescence in situ hybridization for C-MYC.
• Assessment of protein expression including CD markers, OCT4, STAT signaling proteins, p53, MIB1, BCL2, BCL6, CXCR4, and NF-κB pathway components.

Main Results:

• All tDLBCL expressed CD79a; 98% expressed CD20. One case showed OCT4 expression and C-MYC rearrangement.
• Active STAT signaling (pSTAT1/pSTAT3) was observed in 82% of cases; canonical NF-κB signaling was active in 84%.
• Most cases (77%) were non-germinal center type, with rare C-MYC (6%) and BCL2 (4%) rearrangements, but common BCL6 rearrangement (48%). High CXCR4 expression correlated with shorter progression-free survival (p=0.003).

Conclusions:

• tDLBCL are of non-germinal center/post-germinal center origin, typically not hyperproliferative, with unlikely TP53 mutations.
• STAT and NF-κB signaling pathways are active in tDLBCL.
• CXCR4 expression may serve as a novel prognostic marker for tDLBCL, warranting further investigation in larger cohorts.