Primary follicular lymphoma of the testis in childhood: an entity with peculiar clinical and molecular characteristics.
OBJECTIVE
Paediatric primary follicular lymphoma of the testis (PPFLT) is exceptional: the few reported cases seem to lack BCL-2 gene rearrangement and/or protein expression. The aim of this study was to characterise a PPFLT arising in a 4 year old boy.


METHODS
This case was characterised using conventional histological analysis, immunohistochemistry, and a polymerase chain reaction based method for the detection of immunoglobulin V(H) chain rearrangements.


RESULTS
The neoplasm was staged I(E)/A; left orchiectomy and chemotherapy were performed, producing complete remission. Histology showed a predominantly follicular lymphoid infiltrate mainly composed of centroblast-like cells. The phenotype was CD20(+), CD79a(+), CD10(+), bcl-6(+), B cell specific activating protein(+), kappa light chain(+), CD30(-/+), interferon regulating factor 4(-/+), c-myc(-/+), lambda light chain(-), CD3(-), bcl-2(-), p53(-), cytokeratin(-), and placental alkaline phosphatase(-). Lymphomatous elements were found within a CD21(+) follicular dendritic cell network and 70% were positive for Ki-67/MIB-1. Molecular analysis revealed monoclonal immunoglobulin heavy chain gene rearrangement and BCL-6 mutations, in the absence of BCL-2 major breakpoint and BCL-2 minor cluster region rearrangements, p53 mutations, and death associated protein kinase gene hypermethylation.


CONCLUSIONS
These findings suggest a different pathogenesis of PPTFL compared with adult follicular lymphoma and might explain its favourable course in spite of aggressive histology.
Pileri
S A
SA
Pathology and Clinical Units of the Institute of Haematology and Clinical Oncology L. and A. Seràgnoli, University of Bologna, Italy. pileri@almadns.unibo.it
Sabattini
E
E
Rosito
P
P
Zinzani
P L
PL
Ascani
S
S
Fraternali-Orcioni
G
G
Gamberi
B
B
Piccioli
M
M
Vivenza
D
D
Falini
B
B
Gaidano
G
G
D002675:Child, Preschool; D004268:DNA-Binding Proteins / Q000235:genetics; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D006801:Humans; D016130:Immunophenotyping; D008224:Lymphoma, Follicular / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D008297:Male; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051560:Proto-Oncogene Proteins c-bcl-6; D013736:Testicular Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors