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 with controversial management guidelines. Wilhelm et al. followed 41 patients with a known extra-thyroid malignancy and ITNs; 35 of them met the criterion for biopsy (nodule ≥ 1 cm). Pathology revealed four papillary thyroid cancers and five micropapillary thyroid cancers. Only two metastatic cancers were detected. Clinical history (history of radiation, age, endocrine syndromes), TSH, nodule size, and sonographic features are important to determine which nodule(s) should be followed or biopsied. However, existing guidelines do not specifically address how to approach ITNs detected on CT scans in such a specific patient population. Thyroid lymphoma represents about 5 % of thyroid