Article

Molecular profile and clinical-pathologic features of the follicular variant of papillary thyroid carcinoma. An unusually high prevalence of ras mutations.

Departments of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, 231 Albert Sabin Way, PO Box 670529, Cincinnati, OH 45267-0529, USA.
American Journal of Clinical Pathology (Impact Factor: 3.01). 08/2003; 120(1):71-7. DOI: 10.1309/ND8D-9LAJ-TRCT-G6QD
Source: PubMed

ABSTRACT The follicular variant (FV) of papillary thyroid carcinoma is characterized by a follicular growth pattern and cytologic features of papillary carcinoma. ret/PTC rearrangements are common in classic papillary thyroid carcinoma (PTC) and PAX8-PPAR gamma and ras mutations in follicular thyroid carcinoma. Their prevalence in FV has not been established. We studied these genetic alterations and clinical-pathologic features in 30 FV cases and compared those with 46 non-FV papillary carcinomas. FV cases revealed 1 ret/PTC rearrangement (3%) and 13 ras mutations (43%). Non-FV cases harbored 13 ret/PTC (28%) (P = .006) and no ras mutations (P = .0002). No PAX8-PPAR gamma was found in either group. FV cases demonstrated a significantly higher prevalence of tumor encapsulation, angiovascular invasion, and poorly differentiated areas and a lower rate of lymph node metastases. These data indicate that the FV of papillary carcinoma has a distinct set of molecular alterations and is characterized by a high frequency of ras point mutations.

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