Anaplastic thyroid carcinoma (ATC) is an uncommun and highly aggressive malignancy. Differentiated follicular and papillary thyroid carcinomas account for most (80-90%) thyroid malignancies with ATC accounting for less than 5%. A diagnosis of ATC is usually fatal with a mean survival of 3-9 months and only 10-15% alive at 2 years. Histologic examination reveals that many of them contain a papillary structure or follicular components in focal areas and genetic alteration is the driving for genesis of cancer and progression. These studies showing that ATC represents a terminal "de-differentiation" of pre-existing differentiated carcinoma. Most of patients are incurable, nevertheless a multimodality approach, incorporating surgery with the aim to obtain complete macroscopic resection and achieve clear resections margins followed by adjuvant treatment RT (radiotherapy) and/or chemotherapy, improve local control and extend the survival. The aim of the present study has been to review a case of a young women with ATC that reports a survival exceeding 6 years.