title: Polyclonal and monoclonal thyroid nodules coexist within human multinodular goiters.
abstract: Although somatic mutations have been identified in a subset of thyroid nodules, the pathogenesis of nodules in multinodular goiters remains unclear. Clonal analysis indicates whether a nodule arises from the polyclonal proliferation of a group of cells or forms a clone from a genetically altered cell. Individual thyroid nodules have been shown to be of polyclonal or monoclonal origin. In this study we examined the clonality of several different nodules in patients with multinodular goiters. Clonality was established using the X-chromosomal probe M27 beta, which detects a multiallelic polymorphism at the locus DXS255 in 90% of females. Twenty-five nodules from 9 multinodular goiters were analyzed; 9 nodules were polyclonal, and 16 were monoclonal. Three goiters contained only polyclonal nodules, whereas 3 contained only monoclonal nodules. Polyclonal and monoclonal nodules coexisted in 3 goiters. In 2 goiters, the monoclonal nodules were shown to derive from different progenitor cells. We conclude that polyclonal and monoclonal nodules may coexist in multinodular goiters and that monoclonal nodules can originate from different cells. The coexistence of polyclonal and monoclonal nodules suggests that different pathogenic mechanisms occur simultaneously or that monoclonal nodules emerge secondarily from a polyclonal population due to a growth advantage from a genetically altered cell.
authors.affiliation: Department of Internal Medicine, Inselspital, Bern, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Kopp
authors.forename: E T
authors.initials: ET
authors.lastname: Kimura
authors.forename: S
authors.initials: S
authors.lastname: Aeschimann
authors.forename: M
authors.initials: M
authors.lastname: Oestreicher
authors.forename: A
authors.initials: A
authors.lastname: Tobler
authors.forename: M F
authors.initials: MF
authors.lastname: Fey
authors.forename: H
authors.initials: H
authors.lastname: Studer
mesh_terms: D000328:Adult; D000368:Aged; D015139:Blotting, Southern; D002999:Clone Cells; D015342:DNA Probes; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific; D004303:Dosage Compensation, Genetic; D005260:Female; D005819:Genetic Markers; D006044:Goiter, Nodular / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D013234:Stem Cells / Q000473:pathology
chemical_list: D015342:DNA Probes; D005819:Genetic Markers; D019003:Deoxyribonuclease HpaII; C047564:CCANNNNNNTGG-specific type II deoxyribonucleases; C024388:CTGCAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific