Study Of Morphologic, Immuophenotypic And Genetic Features And Their Diagnostic Significance For Sporadic Adult Papillary Thyroid Carcinoma

Objective: To explore the morphologic, immuophenotypic and genetic features of papillary thyroid carcinoma (PTC)and their diagnostic significance for sporadic adult papillary thyroid carcinomaMethods: Morphologic studies and immunohistochemical analyses of CK19 Galectin-3 和 HBME-1 were performed on 155 cases of sporadic adult papillary thyroid carcinoma and 83 cases of other benign and malignant thyroid disease with frozen and paraffin-embedded tissues. Using nest translation polymerase chain reaction (nest-RT—PCR) and DNA sequencing technique, WT-RET and RET/PTC1,3 chimeric gene was amplified and sequenced in 66 cases of papillary thyroid carcinoma and 36 cases of the control with frozen and paraffin-embedded tissues. House-keeping gene PGK was used to detect the quality of RNA. Long distance PCR (LD-PCR) was performed to detect and analyze the breakpoint characterization in DNA of the RET/PTC oncogene . PCR was employed to detect BRAF (V599E) mutation in frozen and paraffine-embeded thyroid tissue with House-keeping gene β-Actin was used to detect the quality of DNA..Results: (1) 16. 4 percent cases (18/110) of PTC without lymphocytic thyroiditis invaded in the tissues around the tumor and was higher than the ratio(4.4%) of those cases with lymphocytic thyroiditis (p<0. 05) . 77 percent cases (57/74) of typical PTC were older than 40 and higher than the ratio in follicular variant and oxyphilic variant(28. 6% and 33.3 % .respectively). Lymph node metastasis ratio in typical PTC 55. 4%(41/74)was higher than micro-PTC 27.5%(11/40), but lower than tall cell variant 100%(9/9). 134 cases of PTC had been followed up for 8~12years and 31.3% (42/134) had been replied. Five-year survival rate was 100% (13/13) and Ten-year survival rate was 96. 6%(28/29) respectively. (2) CK19, RET, galectin-3 and HBME-1 were all diffuse and strong expressed in PTC and higher than in benign and malignant thyroid disease. Positive ratio of the four markers in PTC were 87. 1%(135/155), 71. 0%(110/155), 91.6%(142/155) and 95.5%(148/155) respectively. The positive ratio of CK19, RET and galectin-3 in hashimoto' s disease were higher than in follicular adenomas and nodular goiters. The expression of Galectin-3 in FVPTC was stronger than FTC, and its positive ratio in both FVPTC and FTC were higher than FA. Statistical data show that the expression of galectin-3 in PTC was related to the lymph node matastasis. But there were no any correlation between the expression of CK19, RET, HBME-1 and clinicopathologic parameters. (3)In sixty-six cases of PTC, nineting cases (28.2%) were expressed wild-type RET(WT-RET) and only one adenoma(12. 5%) was expressed WT-RET. RET/PTC chimeric gene was detected only in PTC (21.2%) . Among them, 5 cases (7. 6%) were RET/PTCl and 9 cases (13. 6%)were RET/PTC3 repectively and only one PTC expressed RET/PTCl, 3 simultaneously. Statastic data did not show any correlation between the expression of WT-RET and RET/PTCl ,3 with clinicopathologic parameters (p>0. 05) . (4)The genomic DNA of RET/PTCl was 3091 bp and the breakpoint did not have insertion, deletion and duplicate sequence. The genomic DNA of RET/PTC3 and it' s reciprocal fusion DNA (RET-ELE1) were 2119 bp and 1568 bp, and the breakpoint was in the Alu repeat sequence of ELE1 gene and there is a polyA near the breakpoint. At the fusion point of RET/PTC3 .There are 2 bp (aa) and 5bp (gttcc) deletion in ELE1 and RET gene , respectively. (5) BRAF mutation was detected only in PTC (56%) and had a high prevalence in both classic and tall cell types (70% and 67% ). However , follicular types of PTC and other benign and malignantV599Ethyroid disease were BRAF mutation negative. Statistical data did notV599Eshow any correlation between the BRAF mutation with clinicopathologic features of PTC (p>0. 05) . There was no overlap between BRAF mutations and RET/PTC rearrangements.Conclusions: (l)PTC with lmphocytic thyroditis maybe have a good prognosis. Compared with typical PTC,the prognosis of follicular variant...