Correlation between osteopontin messenger RNA expression and microcalcification shown on sonography in papillary thyroid carcinoma.
The aims of this study were to investigate the correlation between osteopontin expression and microcalcification seen on sonograms of human papillary thyroid carcinoma and to explore the mechanism of microcalcification in these tumors. Real-time reverse transcription-polymerase chain reaction and immunohistochemistry were used to determine expression levels and locations of osteopontin in 56 pathologically verified papillary thyroid carcinoma nodules. Osteopontin expression correlated with microcalcification and other sonographic signs recorded preoperatively. Osteopontin expression in the papillary thyroid carcinoma group was significantly enhanced compared with the control group for both messenger RNA and protein levels (P < .05). Osteopontin expression was significantly related to microcalcification and lymph node metastasis (P < .05), as shown on sonography. Our results suggest a possible role for osteopontin in the formation of microcalcification in papillary thyroid carcinoma; the sonographic signs can reflect the pathologic and biological behavior of these tumors.