Novel markers in pediatric-type follicular lymphoma

Virchows Arch. 2019 Dec;475(6):771-779. doi: 10.1007/s00428-019-02681-y. Epub 2019 Nov 4.


The aim of this study was to review the histopathological, phenotypic, and molecular characteristics of pediatric-type follicular lymphoma (PTFL) and to assess the diagnostic value of novel immunohistochemical markers in distinguishing PTFL from follicular hyperplasia (FH). A total of 13 nodal PTFLs were investigated using immunohistochemistry, fluorescence in situ hybridization (FISH), and PCR and were compared with a further 20 reactive lymph nodes showing FH. Morphologically, PTFL cases exhibited a follicular growth pattern with irregular lymphoid follicles in which the germinal centers were composed of numerous blastoid cells showing a starry-sky appearance. Immunohistochemistry highlighted preserved CD10 (13/13) and BCL6 (13/13) staining, CD20 (13/13) positivity, a K light chain predominance (7/13), and partial BCL2 expression in 6/13 cases (using antibodies 124, E17, and SP66). The germinal center (GC)-associated markers stathmin and LLT-1 were positive in most of the cases (12/13 and 12/13, respectively). Interestingly, FOXP-1 was uniformly positive in PTFL (12/13 cases) in contrast to reactive GCs in FH, where only a few isolated positive cells were observed. FISH revealed no evidence of BCL2, BCL6, or MYC rearrangements in the examined cases. By PCR, clonal immunoglobulin gene rearrangements were detected in 100% of the tested PTFL cases. Our study confirmed the unique morphological and immunophenotypic features of PTFL and suggests that FOXP-1 can represent a novel useful diagnostic marker in the differential diagnosis between PTFL and FH.

Keywords: Differential diagnosis; FOXP-1; Immunohistochemistry; Pediatric-type follicular lymphoma.

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Diagnosis, Differential
  • Forkhead Transcription Factors / metabolism*
  • Humans
  • Immunohistochemistry / methods
  • Immunophenotyping / methods
  • Lymphoma, B-Cell / diagnosis
  • Lymphoma, B-Cell / metabolism
  • Lymphoma, B-Cell / pathology*
  • Lymphoma, Follicular / diagnosis
  • Lymphoma, Follicular / metabolism*
  • Lymphoma, Follicular / pathology*
  • Male
  • Repressor Proteins / metabolism*
  • Stathmin / metabolism
  • Young Adult


  • FOXP1 protein, human
  • Forkhead Transcription Factors
  • Repressor Proteins
  • STMN1 protein, human
  • Stathmin