Type
It is important to remember that not all lumps and bumps in the neck are cancer. Some thyroid nodules are benign (non-cancerous), and others on the borderline between benign and malignant (cancerous). Often, the definitive diagnosis of the type of cancer is not fully determined until after the thyroid nodule has been removed. After diagnosing a patient with anaplastic thyroid cancer (ATC), a pathologist will need to determine what type of cancer it is, the grade of the tumor, and the stage of the cancer. Doctors often establish a preliminary disease stage based on physical exam and findings on imaging, which help to identify the extent of disease. In patients who undergo surgery, a more well-defined disease stage is determined based on pathology after surgery.
Poorly-differentiated Thyroid Cancer
This type of cancer is not well-differentiated like papillary and follicular cancer, but is not fully undifferentiated like ATC. It exists on a spectrum between the two, both pathologically and clinically. Overall, these cancers exhibit more aggressive behavior and have lower cure rates than do well-differentiated cancers. However, they have a more favorable prognosis than does ATC.
Anaplastic (undifferentiated) Thyroid Cancer
This is a very aggressive thyroid cancer that is completely undifferentiated. This means that the cancer cells have lost all similarities to normal thyroid cells. This type of cancer is generally very difficult to cure. If it is caught early and the tumor still is completely within the thyroid gland, surgical removal may be an option. Surgery is most often followed by external beam radiation therapy as well as cytotoxic chemotherapy. If the tumor has already invaded surrounding structures and is considered unresectable, then combined chemotherapy and radiation treatment will be given.
