Molecular analysis of Hurthle cell neoplasms by gene profiling

Abstract

Though Hurthle cell tumors are considered a variant of follicular lesions, recent data have suggested that Hurthle cell carcinomas may be more closely related to papillary thyroid carcinomas (PTCs). These studies were conducted to determine if molecular profiling can enhance our understanding of Hurthle cell neoplasms. Thirteen Hurthle cell tumors (9 adenomas, 4 carcinomas) were analyzed with the Affymetrix HU-95 gene chips. Molecular profiles obtained were compared to 14 follicular adenomas (FAs), 7 follicular carcinomas (FCs), 10 PTCs, 11 follicular variant PTCs, and 9 hyperplastic nodules. Hierarchical cluster analysis defined potential groupings and differences among samples. Hurthle cell carcinomas grouped with FCs 100% of the time. Surprisingly, Hurthle cell adenomas clustered with FCs when compared to FAs and FCs in 8/9 (88%) cases. All 13 Hurthle cell lesions migrated as a distinct group separate from PTCs and FVPTCs. Finally, all Hurthle cell lesions clustered with FCs, rather than PTCs, when compared to both groups. Molecular profiles of Hurthle cell adenomas and carcinomas are more similar to FCs than benign lesions or PTCs. Although Hurthle cell adenomas generally behave in a benign fashion, the molecular signature of these lesions suggests a more malignant phenotype.