Uncommon Site of Metastasis and Prolonged Survival in Patients with Anaplastic Thyroid Carcinoma: A Systematic Review of the Literature

Anaplastic thyroid carcinoma (ATC) is a very rare, highly aggressive malignant thyroid tumor with an overall survival from 3 to 5 months in most of the cases. Even the modern and intensive treatments seem not to be enough to provide a cure, also for the resectable ones, and the role of chemotherapy is still unclear but does not seem to prolong survival. Nevertheless, some patients survive longer and have a better outcome, even in the presence of metastasis, than what the literature reports. We present the case of a 64-year-old female affected by ATC, treated on February 2018 with surgery followed by chemoradiation. One year after surgery, the patient developed a subcutaneous recurrence that was radically resected and is still alive 29 months after the diagnosis. We propose a systematic review of the literature to deepen the knowledge of the prognostic factors of ATC with the aim to recognize and select the patients with a better outcome, even if metastatic, and to describe a very uncommon site of metastatization.