A rare form of thyroid cancer making up less than 1% of such cancers and usually presents as a rapidly growing neck mass.
Extremely aggressive neoplasm with patient death occurring a few months after diagnosis.
Accounts for more than half of the 1200 deaths annually attributed to thyroid cancer in the U.S.
Patients often develop hoarseness, dysphagia, and dyspnea.
Most patients have a large, firm palpable mass in the thyroid with or without cervical lymphadenopathy.
Metastatic assessment office reveals locoregional disease and distant metastases.
The most common site of distant metastases is the lungs, followed by bones and brain.
Can often arise from and can coexist with differentiated thyroid cancer, but can also occur de novo.
Diagnosis should be suspected in patients with a history of long-standing differentiated thyroid cancer that have symptoms and findings as noted above.
Mean survival ranging from 4 to 12 months and a 5-year survival rate ranging from 1% to 7.1%.
The diagnosis portends such a poor outcome it is classified as Stage IV regardless of tumor, node or metastatic status, 2% of all thyroid cancers.
Approximately half of affected individuals have distant metastases present at the time of diagnosis.
Most common cause of death is suffocation caused by tumor obstructing the thoracic outlet.
Few patients survive longer than 1 year.
Development of anaplastic thyroid cancer is considered part of the natural course of untreated differentiated thyroid cancer.
Approximately 2% of differentiated thyroid cancer are believed to develop into anaplastic tumors.