Get access

Follicular variant of papillary thyroid carcinoma: Genome-wide appraisal of a controversial entity

Authors

  • Volkert B. Wreesmann,

    1. Laboratory of Epithelial Cancer Biology, Memorial Sloan-Kettering Cancer Center, New York, New York
    2. Head and Neck Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
    • These authors contributed equally to the completion of this manuscript.

  • Ronald A. Ghossein,

    1. Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
    • These authors contributed equally to the completion of this manuscript.

  • Michael Hezel,

    1. Laboratory of Epithelial Cancer Biology, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
  • Debenranrath Banerjee,

    1. Laboratory of Epithelial Cancer Biology, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
  • Ashok R. Shaha,

    1. Head and Neck Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
  • R. Michael Tuttle,

    1. Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
  • Jatin P. Shah,

    1. Head and Neck Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
  • Pulivarthi H. Rao,

    1. Department of Pediatrics, Baylor College of Medicine, Houston, Texas
    Search for more papers by this author
  • Bhuvanesh Singh

    Corresponding author
    1. Laboratory of Epithelial Cancer Biology, Memorial Sloan-Kettering Cancer Center, New York, New York
    2. Head and Neck Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
    • Director, Laboratory of Epithelial Cancer Biology, Head and Neck Service, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021
    Search for more papers by this author

Abstract

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.

Ancillary