Final answer:
Anaplastic thyroid carcinoma is a type of thyroid cancer prevalent in the elderly with poor prognosis and presents as a rapidly enlarging neck mass. Goiter is a common symptom of various thyroid disorders and early treatment is essential for positive outcomes.
Step-by-step explanation:
The type of thyroid cancer that is common in the elderly, has a poor prognosis, and is characterized by a rapidly enlarging neck mass could be anaplastic thyroid carcinoma. In general, a goiter indicates an abnormal enlargement of the thyroid gland, which can occur due to various conditions, including iodine deficiency, thyroid tumors, excessive Thyroid Stimulating Hormone (TSH), and Long-Acting Thyroid Stimulator (LATS), as seen in Graves' disease or Hashimoto's thyroiditis.
Hashimoto's thyroiditis is an autoimmune disorder that can lead to hypothyroidism and is associated with symptoms like goiter, cold intolerance, muscle weakness, and memory loss. It is crucial to diagnose and treat thyroid disorders early to improve outcomes; for instance, if a goiter is detected and treated early, the thyroid can often return to normal size.