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Follicular variant of papillary thyroid carcinoma: Genome‐wide appraisal of a controversial entity
Author(s) -
Wreesmann Volkert B.,
Ghossein Ronald A.,
Hezel Michael,
Banerjee Debenranrath,
Shaha Ashok R.,
Tuttle R. Michael,
Shah Jatin P.,
Rao Pulivarthi H.,
Singh Bhuvanesh
Publication year - 2004
Publication title -
genes, chromosomes and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.754
H-Index - 119
eISSN - 1098-2264
pISSN - 1045-2257
DOI - 10.1002/gcc.20049
Subject(s) - thyroid carcinoma , follicular phase , thyroid cancer , pathology , comparative genomic hybridization , thyroid , immunohistochemistry , follicular thyroid cancer , biology , cancer research , papillary thyroid cancer , medicine , chromosome , gene , endocrinology , genetics
The majority of thyroid tumors are classified as papillary (papillary thyroid carcinomas; PTCs) or follicular neoplasms (follicular thyroid adenomas and carcinomas; FTA/FTC) based on nuclear features and the cellular growth pattern. However, classification of the follicular variant of papillary thyroid carcinoma (FVPTC) remains an issue of debate. These tumors contain a predominantly follicular growth pattern but display nuclear features and overall clinical behavior consistent with PTC. In this study, we used comparative genomic hybridization (CGH) to compare the global chromosomal aberrations in FVPTC to the PTC of classical variant (classical PTC) and FTA/FTC. In addition, we assessed the presence of peroxisome proliferator‐activated receptor‐gamma ( PPARG ) alteration, a genetic event specific to FTA/FTC, using Southern blot and immunohistochemistry analyses. In sharp contrast to the findings in classical PTC (4% of cases), CGH analysis demonstrated that both FVPTC (59% of cases) and FTA/FTC (36% of cases) were commonly characterized by aneuploidy ( P = 0.0002). Moreover, the pattern of chromosomal aberrations (gains at chromosome arms 2q, 4q, 5q, 6q, 8q, and 13q and deletions at 1p, 9q, 16q, 17q, 19q, and 22q) in the follicular variant of PTC closely resembled that of FTA/FTC. Aberrations in PPARG were uniquely detected in FVPTC and FTA/FTC. Our findings suggest a stronger relationship between the FVPTC and FTA/FTC than previously appreciated and support further consideration of the current classification of thyroid neoplasms. © 2004 Wiley‐Liss, Inc.