Anaplastic thyroid carcinoma: an ultrastructural study of 10 cases

[Biphasic sarcomatoid carcinoma of the thyroid: an exceptional localization of a rare tumor]

Thyroid sarcomatoid carcinoma is a rare and aggressive neoplasm composed of a follicular carcinoma which is contiguous or admixed with a pleomorphic spindle cell component. We report the case of a thyroid tumor reputed to have a poor outcome, in a 62-year-old woman. The radical thyroidectomy specimen was totally invaded. Results of immunoperoxidase staining for thyroglobulin and epithelial markers were positive in the areas of follicular carcinoma and negative in the sarcomatous component. The patient died a few days later due to septic shock. The epithelial and mesenchymal components of thyroid carcinosarcoma were both part of the neoplastic parenchyma and evolved from a single common stem cell, in agreement with the hypothesis that the tumors are of monoclonal origin. The definition of this tumor as its histogenesis and prognostic are discussed.

Anaplastic transformation of thyroid cancer: review of clinical, pathologic, and molecular evidence provides new insights into disease biology and future therapy

BACKGROUND

Anaplastic thyroid cancer ranks among the most lethal of all human malignancies. Its rarity and rapidly fatal course have made it a difficult cancer to both study and treat. Unfortunately, there has been little progress in the management and control of this malignancy. Anaplastic transformation, or the intratumoral evolution of anaplastic carcinoma from pre-existing differentiated thyroid cancer, has become a well-accepted process, despite a limited understanding of its underlying mechanisms.

METHODS

It is through review of the literature that an understanding of the aggressive disease biology can be developed. The aim of this review is to evaluate the relevant clinical, pathologic, and molecular studies to develop an insight into the mechanisms that underlie the intratumoral molecular evolution of anaplastic thyroid carcinoma.

RESULTS/CONCLUSION

It is based on an understanding of this process that effective treatments for this aggressive malignancy are currently being developed.

Anaplastic type of medullary thyroid carcinoma. An ultrastructural and immunohistochemical study

A case of anaplastic type of medullary thyroid carcinoma is presented. Immunoperoxidase study revealed calcitonin within the tumor cells, which also showed argyrophilia. At ultrastructural examination the tumor also displayed mucoid and squamous differentiation. This multidirectional differentiation (endocrine and exocrine) underlies the difficulty of ascribing a precise histogenesis to this tumor.