Molecular Aberrance in Papillary Thyroid Microcarcinoma Bearing High Aggressiveness: Identifying a "Tibetan Mastiff Dog" From Puppies

Today the most common differentiated thyroid cancer in many countries is papillary thyroid microcarcinoma (PTMC). Although the majority of PTMCs exhibit an indolent clinical course, a few possess high risk for aggressiveness with tumor invasion, metastasis, and even patient mortality. This imposes significant confusion and often dilemma in the clinical management of PTMC. The present review summarizes the molecular pathogenesis, particularly the major genetic alterations, of PTMC that may have prognostic values in assisting risk stratification of this cancer and identification of the most aggressive cases from the many well-behaving cases. J. Cell. Biochem. 117: 1491-1496, 2016.