Endocrine Abstracts

Introduction: Anaplastic thyroid cancer has long been considered as a mesenchymal tumor (sarcoma). To date, it is difficult to differentiate between the two types. Radio-induced sarcomas of the head and neck are a very rare entity. Their annual incidence is 0.06 to 0.17%.

Observation: We report the case of a 83-year-old patient, with a history of breast neoplasia treated with radiotherapy 7 years ago. Followed for a year for papillary carcinoma of the thyroid in its papillo-vesicular form classified PT3NxMx. During the follow-up, the cervical ultrasound was normal and the Tg was at zero. After 3 months, she had a 5 cm cervical mass, with lymph nodes; and a very fast evolution with significant compressive signs, and lung metastasis. Fine needle aspiration evokes anaplastic carcinoma. This mass fistulised spontaneously, and the anatomopathological study concluded a radio-induced sarcoma. The patient died quickly after the diagnosis.

Discussion: The long-term carcinogenic potential of ionizing radiation is well established. Although pleomorphic undifferentiated thyroid sarcoma (WHO 2013 classification) is extremely rare, this diagnosis should be considered in patients with rapidly progressive mass with compressive signs (similar signs to anaplastic carcinoma). In order to propose a treatment by complete and wide surgical exeresis. Although traditionally, they are considered very aggressive tumors with poor prognosis.