Expression of Human Telomerase Reverse Transcriptase and Computerized Morphometric Study in Thyroid Follicular Neoplasms

• Main Authors: Sheng-Lan Wang, 王勝嵐
• Other Authors: Chee-Yin Chai
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/67958061406366912219

碩士 === 高雄醫學大學 === 醫學研究所碩士班 === 93 === Purpose: The differential diagnosis between follicular adenoma (FA) and follicular carcinoma (FC) of thyroid can be difficult in routine practice of surgical pathology because the diagnosis of FC is strict and determined by the presence of capsular and/or vascular invasion in the tumor. These features may be equivocally presented in the histologic sections and need serial sections to be evaluated. On the other hand, telomerase is expressed in many human cancers and is thought to contribute to their immortality. Human telomerase reverse transcriptase (hTERT) is the major determinant of human telomerase activity, and its expression is indicative of unlimited replication. According, computerized morphometry is a scientific tool to evaluate cellular changes and it can enhance the interpretation of morphologic features by the transformation of qualitative indices of pathologic changes in cells to a qualitative form. In many other tumors, such an application of morphometric study combined with the clinical data and the experience of the pathologist can lead to greater accuracy and precision in surgical pathology diagnoses. The aim is to investigate the value of immunohistochemical stain of hTERT and computer-assisted nuclear morphometry in the differential diagnosis of follicular neoplasms. Moreover, we also would like to evaluate the value of hTERT immunoexpression and computerized morphometric analysis in the prediction of the patient prognosis. Materials and methods: This is a case-control study that examined the expression of hTERT by immunohistochemistry in 36 cases of thyroid FC and 36 cases of FA who were with age- and sex matched. At the same time, the computerized morphometric study was performed and the following four nuclear parameters were included and calculated in a total 72 follicular neoplasms: the mean nuclear area, the mean nuclear perimeter, the largest to the smallest diameter ratio of the nuclei, and the coefficient of variation of the nuclear area. The 36 cases of FC were categorized into two groups according to sex, age, size of the primary lesion, presence or absence of vascular invasion, and metastases of the tumor, all of which were potentially correlated with prognosis. The correlations between the subgroups associated with known prognostic factors in the hTERT immunoexpression and computerized morphometric study were analyzed. Results: The results revealed 23 cases of FC and 14 cases of FA showed high expression of hTERT that varied from moderate to strong immunoreactivity. The remaining cases showed weak or negative staining. The difference between FA and FC was statistically significant (P<0.05). The results demonstrate hTERT immunoexpression is not associated with the selected prognostic parameters. On the other hand, all nuclear variables were also significantly different (P<0.05) between FA and FC in computerized morphometric study, and no selected parameter had prognostic significance in FC. Conclusion: The immunohistochemical staining for hTERT and computerized morphometric study may be an ancillary marker and technique for differential diagnosis between FA and FC. Neither hTERT immunoexpression nor nuclear morphometry can seem able to provide any correlation with known prognostic factor and can be served as an additional predictor factor for biologic behavior.