Uncommon types of thyroid cancer.
Anaplastic carcinoma of the thyroid is rare, making up 5% to 14% of primary malignant thyroid neoplasms. Lymphoma of the thyroid is even rarer, accounting for only 1% to 2% of thyroid malignancies. Other even rarer tumors of the thyroid, such as liposarcoma and angiosarcoma, have also been described. Although these thyroid tumors are rare, it is very important to recognize them because they may present as medical emergencies and constitute a challenge for endocrinologists, surgeons, radiotherapists, and oncologists. Anaplastic carcinoma grows rapidly and has a dismal prognosis. A significant number of patients with anaplastic carcinoma have areas of well differentiated thyroid carcinoma, which supports the hypothesis that anaplastic thyroid carcinoma arises from a pre-existing well differentiated thyroid carcinoma. Younger patients do better than older patients, and those diagnosed at an earlier stage do better than those with metastases at presentation. Multimodality therapy with surgery, radiotherapy, and chemotherapy appears to be of value. Lymphoma of the thyroid may be a primary disease or may involve the gland as part of a systemic disease. It is not usually suspected before surgery or fine-needle aspiration biopsy. Radiotherapy alone, if the disease is limited to the neck, produces good results; however, in patients with mediastinal extension, chemotherapy is indicated.
Samaan
N A
NA
Section of Endocrinology, University of Texas MD Anderson Cancer Center, Houston.
Ordoñez
N G
NG
D002277:Carcinoma / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis / Q000473:pathology; D008297:Male; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology