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.
Pathology and Clinical Units of the Institute of Haematology and Clinical Oncology L. and A. Seràgnoli, University of Bologna, Italy. pileri@almadns.unibo.it
S A
SA
Pileri
E
E
Sabattini
P
P
Rosito
P L
PL
Zinzani
S
S
Ascani
G
G
Fraternali-Orcioni
B
B
Gamberi
M
M
Piccioli
D
D
Vivenza
B
B
Falini
G
G
Gaidano
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