title: Impact of the reactive microenvironment on the bone marrow involvement of follicular lymphoma.
abstract: OBJECTIVE
  Follicular lymphoma (FL) is associated with bone marrow (BM) involvement in approximately 40-70% of cases. Previous studies have suggested that the immune-microenvironment of FL plays an important role in the clinical behaviour of the disease. To investigate the role of the microenvironment in BM involvement of FL, we performed immunophenotypical analysis of the reactive cell populations in lymph nodes (LN) and corresponding BM of 35 patients with FL. Microenvironment patterns of BM infiltrates were compared to the corresponding features of the LN in cases with BM manifestation, and the LN microenvironment was compared in FL cases with and without BM involvement.
  
  
  RESULTS
  Automated image-segmentation-based quantitation was performed in whole digital slides of tissue microarrays of formalin-fixed paraffin-embedded tissue biopsies. We found significantly more CD8(+) T lymphocytes, forkhead box protein 3 (FoxP3)(+) T lymphocytes and CD68(+) macrophages and fewer PD1(+) T lymphocytes in the BM than in the matching LN samples. Furthermore, we observed significantly fewer CD8(+) T cells and CD68(+) macrophages in cases involving the BM compared to those localized only to the LNs.
  
  
  CONCLUSIONS
  Our study showed that different tumour cell growth in the LN and BM may generate different microenvironments, and suggested that the reduced number of cytotoxic T lymphocytes and macrophages in LNs favours BM infiltration of neoplastic cells in FL.
authors.affiliation: 1st Department of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Hajnalka
authors.initials: H
authors.lastname: Rajnai
authors.forename: Csaba
authors.initials: C
authors.lastname: Bödör
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Balogh
authors.forename: Eva
authors.initials: E
authors.lastname: Gagyi
authors.forename: Judit
authors.initials: J
authors.lastname: Csomor
authors.forename: Tibor
authors.initials: T
authors.lastname: Krenács
authors.forename: Erika
authors.initials: E
authors.lastname: Tóth
authors.forename: András
authors.initials: A
authors.lastname: Matolcsy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology*; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008224:Lymphoma, Follicular / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000473:pathology; D059016:Tumor Microenvironment
chemical_list: D051858:Forkhead Transcription Factors