Thyroid often carcinomas, although cancer can occur in any tissue that the thyroid consists of, including cancer of C-cells and lymphomas. Cancers from other sites also rarely lodge in the thyroid. Radiation of the head and neck presents a risk factor for thyroid cancer, and cancer is more common in women than men, occurring at a rate of about 2:1. In most cases, thyroid cancer presents as a painless mass in the neck. It is very unusual for thyroid cancers to present with other symptoms, although in some cases cancer may cause hyperthyroidism. Most malignant thyroid cancers are papillary, followed by
Computed tomography of the thyroid malignancies. Non-Hodgkin’s lymphoma is the most common type and can be secondary to generalized lymphoma or a primary tumour. Primary thyroid lymphoma usually pre-exists with Hashimoto’s thyroiditis. On CT scans with and without contrast, lymphomas tend to have low attenuation values. Thyroid lymphomas have variable appearance and mostly manifest as a solitary mass (80 %). They may also manifest as multiple nodules (15 % to 20 %) or as a bulky mass replacing the entire gland with extra-thyroid extension (Figs. 11 and and12).12). The presence of cervical lymphadenopathy supports such a diagnosis. Although it is uncommon, tumour necrosis has been