Expression of CD30 ligand and CD30 receptor in normal thyroid and benign and malignant thyroid nodules

Because the CD30 ligand (CD30L)/CD30 receptor (CD30) system is expressed in certain malignancies, but has not been studied in thyroid nodules, we inve stigated its immunohistochemical expression in 6 normal thyroids (NT) and 1 31 thyroid nodules: 28 colloid nodules (CN), 45 adenomas (15 oncocytic [OA] , 30 follicular [FA]) and 58 carcinomas (15 follicular [FTC], 1 insular [IT C], 6 anaplastic [ATC], 30 papillary [PTC], and 6 medullary [MTC]). NT and CN expressed neither CD30L nor CD30 (CD30L(-)/CD30(-)). Forty percent of OA and 20% of FA showed epithelial coexpression of CD30L and CD30, and inters titial expression of CD30L, which was also observed in the surrounding norm al tissue. Within malignancies, epithelial coexpression of CD30L and CD30 w as observed in 7% of FTC, 33% of ATC, 67% of PTC, and 67% of MTC. Only PTC and MTC showed epithelial expression of CD30L in the perinodular tissue wit h similar frequency (80% PTC, 75% MTC). PTC and MTC had the highest proport ion of CD30L(+) or CD30(+) cells, and together with OA, a thus far unreport ed nuclear location of CD30L. In PTC, the proportion of CD30L(+) cells and the prevalence of nuclear location of CD30L correlated inversely and direct ly, respectively, with aggressiveness. Ln conclusion, CD30L/CD30 signaling is activated only past the colloid nodule stage, most frequently in an auto crine fashion.