title: Low stage follicular lymphoma: biologic and clinical characterization according to nodal or extranodal primary origin.
abstract: Studies suggest that primary extranodal follicular lymphoma (FL) is not infrequent but it remains poorly characterized with variable histologic, molecular, and clinical outcome findings. We compared 27 extranodal FL to 44 nodal FL using morphologic, immunohistochemical, and molecular genetic techniques and evaluated the clinical outcome of these 2 similarly staged groups. Eight cases of primary cutaneous follicle center lymphoma were also studied. In comparison to nodal FL, a greater number of extranodal FL contained a diffuse growth pattern (P=0.004) and lacked CD10 expression (P=0.014). Fifty-four percent of extranodal and 42% of nodal FL cases showed evidence of t(14;18), with minor breakpoints (icr, 3'BCL2, 5'mcr) more commonly found in extranodal cases (P=0.003). Outcome data showed no significant differences in overall survival (P=0.565) and progression-free survival (P=0.627) among extranodal, nodal, and primary cutaneous follicle center lymphoma cases. Analysis of all cases by t(14;18) status indicate that the translocation-negative group is characterized by a diffuse growth pattern (P=0.043) and lower BCL2 expression (P=0.018). The t(14;18)-positive group showed significantly better overall survival (P=0.019) and disease-specific survival (P=0.006) in comparison with the t(14;18)-negative group. In low stage FL, the status of t(14;18) seems to be more predictive of outcome than origin from an extranodal versus nodal site.
authors.affiliation: Department of Pathology, Stanford University Medical Center, Stanford Comprehensive Cancer Center, Stanford, CA 94305, USA. okw@stanford.edu
authors.forename: Olga K
authors.initials: OK
authors.lastname: Weinberg
authors.forename: Lisa
authors.initials: L
authors.lastname: Ma
authors.forename: Katie
authors.initials: K
authors.lastname: Seo
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Beck
authors.forename: Reetesh K
authors.initials: RK
authors.lastname: Pai
authors.forename: Anjali
authors.initials: A
authors.lastname: Morales
authors.forename: Youn
authors.initials: Y
authors.lastname: Kim
authors.forename: Uma
authors.initials: U
authors.lastname: Sundram
authors.forename: Daryl
authors.initials: D
authors.lastname: Tan
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Horning
authors.forename: Richard T
authors.initials: RT
authors.lastname: Hoppe
authors.forename: Yasodha
authors.initials: Y
authors.lastname: Natkunam
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Arber
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002140:California / Q000453:epidemiology; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology*; D008224:Lymphoma, Follicular / Q000235:genetics / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015996:Survival Rate; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor