Solid variant of papillary thyroid carcinoma - Incidence, clinical-pathologic characteristics, molecular analysis, and biologic behavior
ABSTRACT Solid variant is a rare and poorly characterized variant of papillary thyroid carcinoma. In this study we analyzed 20 primary cases of the solid variant of papillary carcinoma found in a series of 756 papillary carcinomas operated at the Mayo Clinic between 1962 and 1989. The criteria for classification included predominantly (>70%) solid growth pattern of primary tumor, retention of cytologic features typical of papillary carcinoma, and absence of tumor necrosis. For each case of the solid variant, a control case of classical papillary carcinoma matched by age, sex, tumor size, and length of follow-up was selected. The follow-up ranged from 6 to 32 years. Two patients with the solid variant of papillary carcinoma (10%) died from disease 7 and 10 years after initial surgery, while another two patients (10%) are alive with lung metastases. In contrast, the control group had no cases with distant metastases or death from disease. Molecular analyses showed a similar prevalence of RET /PTC rearrangements in both groups. In conclusion, the solid variant of papillary carcinoma is associated with a slightly higher frequency of distant metastases and less favorable prognosis than classical papillary carcinoma. However, it should be distinguished from poorly differentiated thyroid carcinoma, which has a reported lower survival rate compared with the solid variant of papillary carcinoma.
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ABSTRACT: Thyroid cancer is the most common malignancy in endocrine system, composed of four major types; papillary thyroid carcinoma, follicular thyroid carcinoma, anaplastic thyroid carcinoma, and medullary thyroid carcinoma. The incidence of thyroid cancer, especially differentiated thyroid cancer, is increasing in developed countries. Growing body of studies on molecular pathogenesis in thyroid cancer provide clues for further research and diagnostic/therapeutic targets. The general pathological classifications and clinical features of follicular cell derived thyroid carcinomas are overviewed, and recent advances of genetic alterations are discussed in this review.
Article: Науковий журнал Президiї АМН України
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ABSTRACT: RET proto-oncogene rearrangements (ret/PTCs) represent the most common genetic alterations found in papillary thyroid carcinomas (PTCs). Correlation of ret/PTC expression with clinical outcome is controversial. The aim of the present study was to analyze the frequency of RET rearrangements in adult PTCs, and to investigate if ret/PTCs influence biological behavior and clinical features of the cancers. Ret/PTC rearrangements were looked for in tIssue samples of 48 PTCs collected at our institution. Data about clinical and pathological features of the tumors were also reviewed. Three separate association analyses were carried out on the cohort evaluating the effects of, respectively, ret/PTC positivity, preferential RET tyrosine kinase domain (RET-TK) expression, and ret/PTC plus RET-TK positivity, on age, sex, tumor size, staging, number of neoplastic foci, and histological subtype. The genetic study was conducted with the RT-PCR-Southern blot technique. Standard Student's t-test and Fisher exact test were applied for the association analyses. The molecular genetic study demonstrated the positivity of ret/PTC1 and ret/PTC3 in 13 of 48 tumors (27.1%), and an exclusive or preferential RET-TK expression in 17 cases (35.4%). None of the three genetico-clinical analyses showed any significant association between ret/PTC expression and the clinical and pathological features of the cancers. These data indicate that RET rearrangements may not play any distinctive role in driving histotype development and cancer progression in these neoplasms. Moreover, they weaken the possibility of using ret/PTC as a prognostic marker for papillary thyroid carcinomas.European Journal of Endocrinology 06/2003; 148(5):505-13. DOI:10.1530/eje.0.1480505 · 3.69 Impact Factor