Catálogo de publicaciones - libros

Thyroid nodules are common and their management can be difficult and controversial. Clearly, the pathologist has an important role to play in their evaluation. The use of fine needle aspiration biopsy has significantly improved our ability to identify specific high risk disorders and to facilitate their management in an expeditious and cost-effective manner. Patients who require surgery for further confirmation of the disease process rely upon the pathologist to correctly characterize their nodule and pathologists are actively involved in research to clarify the pathogenesis of thyroid disease. There are other areas of thyroid pathology that have seen uniform advances in our understanding of the pathobiology of disease. Most experts accept tall cell or columnar morphology as predictive of more aggressive variants of papillary carcinoma. The recognition of insular carcinomas as an intermediate category of “poorly differentiated carcinoma” has been validated by clinical and molecular studies. The biology of familial genetic alterations in medullary carcinoma has revolutionised patient care. Advances in our understanding of the molecular basis of thyroid cancer will allow more accurate characterization of specific subtypes of neoplasia and malignancy even on single cells obtained at fine needle aspiration biopsy. This should further enhance the usefulness of this technique and better guide the management of patients with a thyroid nodule.

Thyroid tumors are common neoplasms that exhibit a wide range of biologic behavior. Numerous factors have been shown to govern thyrocyte proliferation. In particular, hormones and growth factors likely play a role as promoters of tumor cell growth in genetically transformed cells. In some instances enhanced growth factors and their receptors may serve as survival signals for neoplastic cells. In other instances, however, abnormal forms of growth factor receptors (such as members of the EGF-R/HER2/neu) may also be important in the early stages of cell transformation and chromosomal instability consistent with the clonal composition of thyroid neoplasms. More detailed structure/function studies of growth factor/receptor functional interactions in morphologically characterized thyroid nodules are required. It is anticipated that these studies will identify signaling patterns that will provide the basis for the development of more specific and effective pharmacotherapeutic agents.

As compared with tumors from other organs such as lung, colon, and breast, a limited number of studies have been carried out so far on the involvement of MMPs and TIMPs in thyroid tumorigenesis. Based upon the available data, it is clear that MMPs, especially MMP-2 and MMP-9, and TIMP-1 are involved in thyroid tumor invasion and metastasis. Although TIMP-1 can reduce the invasive potential of thyroid cancer cells in vitro , therapeutic intervention in vivo has not been attempted yet in animal models to inhibit thyroid tumor growth, invasion, and metastasis, using either synthetic MMP inhibitors or TIMPs gene therapy. Clearly, more studies are needed to fully appreciate the important roles of MMPs and TIMPs in thyroid cancer.