A rare diffuse follicular lymphoma with TP53 mutation and copy-neutral loss of heterozygosity at 1p36: insights into diagnosis, disease progression, and literature review.

BACKGROUND

Follicular lymphoma (FL) is a common type of non-Hodgkin lymphoma typically characterized by a nodular growth pattern and the t(14;18) translocation. A rare variant, FL with a predominantly diffuse growth pattern (dFL), lacks this translocation, demonstrates diffuse architecture, and is frequently associated with deletion of 1p36.

CASE PRESENTATION: We report the case of a 43-year-old man who presented with an inguinal mass and was diagnosed with follicular lymphoma showing a predominantly diffuse pattern. Fluorescence in situ hybridization (FISH) analysis was negative for both BCL2 rearrangement and TNFRSF14 (1p36) deletion. Chromosomal microarray (CMA) and next-generation sequencing (NGS) were subsequently performed for further molecular characterization.

RESULTS

CMA revealed copy-neutral loss of heterozygosity (cnLOH) at 1p36 and additional abnormalities involving 16p that were not detectable by FISH. NGS identified a TP53 mutation, a finding not previously reported in dFL and typically associated with more aggressive lymphoma behavior. Although dFL is generally considered an indolent and localized disease, the patient developed axillary recurrence within 1 year, requiring radiation therapy.

CONCLUSION

These findings underscore the importance of comprehensive molecular testing, such as NGS and CMA, to refine prognostic assessment and guide personalized treatment strategies for this rare lymphoma variant.