Aggressive Variants of Follicular- and Parafollicular-Derived Thyroid Carcinoma. Issue 2 (March 2019) - Rossi, Esther Diana
Abstract : Abstract: There are several aggressive variants of thyroid carcinoma including those of papillary thyroid carcinoma, poorly differentiated thyroid carcinoma, anaplastic thyroid carcinoma, and medullary thyroid carcinoma that are important to recognize. Among thyroid malignancies, papillary thyroid carcinoma represents the most common form of endocrine cancer. Papillary thyroid carcinoma usually presents as an indolent cancer with high overall survival rates approaching 96%. However, a minority of thyroid carcinomas with distinctive histopathology (eg, tall cell, columnar cell, solid, hobnail, diffuse sclerosing, and diffuse follicular variant) behaves more aggressively and may not respond to routine treatment, leading to higher mortality. Other aggressive follicular-derived thyroid malignancies are represented by poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma, which are associated with an especially unfavorable prognosis. The most important aggressive parafollicular thyroid malignancy encountered is medullary thyroid carcinoma. This review describes the clinical, pathological, and molecular findings for these aggressive thyroid malignancies and underscores current concepts and controversies related to these tumors.