OBJECTIVEIdentify the significance of variants in papillary thyroid carcinoma (PTC), the role of extracellular matrix (ECM), MMPs, cell adhesion molecular (CAM) and cytokine in lymphatic metastasis in PTC and the value of PET-CT in diagnosis of thyroid carcinoma.

METHODSFive hundred and five cases of PTC which had complete medical records and followed up surveys were selected from the files. Clinical biological characteristic of the histological variants was investigated. Sixty cases of PTC were selected. As the important parts of micro ecosystems, ECM, MMPs, CAMs and cytokine were investigated in use of tissue chip and method of immunohistochemistry. In addition, a group of cases of thyroid carcinoma including PTC was analyzed, follicular thyroid carcinoma and medulla thyroid carcinoma (MTC) and their reports of PET-CT as the initiation.

RESULTSThe variants could be divided into three groups in terms of the rate of cervical lymph node metastasis. The high-metastases group included diffuse sclerosing variant, tall cell variant, column cell variant and diffuse follicular variant. The low-metastases group included macrofollicular variant and papillary microcarcinomas. Others are included in the moderate-metastases group. The rate of cervical lymph node metastasis of each group were 83.0% , 55.5% and 34.1% (P < 0. 05), respectively. The 10-year-survival were 75.3% , 95.8% and 100.0% , respectively. The 20-year-survival were 31.2%, 80.3% and 87.5%, respectively. The positive rate of LN, FN, MMP-2, MMP-9, TIMP-2, CD, Integrinbeta-1, ICAM-1, EGFR, TGFR-beta, VEGF-C and E-Cad in metastasis ranged from 51.6% (Integrinbeta-1) to 98.3% (CD), and that in primartumor ranged from 46.7% (FN) to 98.3% (ICAM-1). The expression of E-cad in primartumor was lower than that in normal tissues (P < 0.05). The sensitivity of PET-CT was 100% and the specificity was 85.7%.

CONCLUSIONSThe characteristic has significant difference among the variants. Individual treatment should be performed in terms of different variants. Furthermore, some molecules play an important role in the lymph node metastasis of PTC and may be considered as the focus of future study. In addition, compared with CT and Bus, PET-CT is more sensitive and has its unquestionable advantage as a whole body examination, especially for staging and detecting micro metastases, though it requires a high expense.