Non-malignant thyroid nodular disease is the growth of normal thyroid tissue causing one or more solid or fluid-filled benign lumps or nodules to develop within the gland. Types of nodules include:

• colloid nodule

• follicular adenoma

• thyroid cyst

• inflammatory nodule

• multinodular goiter, and

• hyperfunctioning thyroid nodule including

  • thyroid enlargement, toxic

  • toxic multinodular goiter, and

  • Plummer's disease.

A thyroid adenoma is the most common benign lesion of the thyroid gland. It is a solitary enclosed nodule of normal thyroid tissue that differs from the surrounding gland and walls of the rest of the thyroid gland.

The cause is indeterminate. However, non-malignant thyroid nodular disease is considered by the Department of Veterans Affairs to be a radiogenic disease caused by ionizing radiation. Veterans that were exposed to radiation while in the service are referred to as "atomic veterans".

Benign nodules are usually not dangerous; however they can cause compression on the trachea if they become too large. The nodule often grows slowly over many years. Signs and symptoms are slow to develop. There maybe a noticeable lump or enlarged lymph nodes in the neck that may indicate a thyroid-related problem. It may compress surrounding tissue. It is usually more than a quarter of an inch in diameter that may protrude from the neck's surface or may form in the thyroid gland itself. Most nodules of the thyroid produce little or no thyroid hormone; occasionally a nodule begins to produce an excessive amount of thyroid hormone resulting in hyperthyroidism. Symptoms such as dysphagia, dysphonia or stridor rarely develop. Occasionally, there is bleeding into the tumor which causes a sudden increase in size, local pain and tenderness. This may be accompanied by symptoms of thyrotoxicosis.

Physical examination will reveal a small, soft and mobile nodule often half an inch or more in size that is palpable and may be seen. A laboratory test to detect levels of thyroid stimulating hormone (TSH) in the blood is done to document thyroid function, and to determine the presence of hypothyroidism or hyperthyroidism. An ultrasound is done to determine if the nodule is solid or a cyst and how many nodules are present. A thyroid scan (radionuclide) will show if the nodules are benign (hot) or malignant (cold). Tumors that take up the dose of radioactive iodine are called hot and are nearly always benign or non-malignant. A fine needle aspiration (FNA) is done to distinguish benign and malignant thyroid nodules.

Treatment of benign thyroid nodules includes periodic monitoring or being treated with levothyroxine to suppress the nodule growth. If the nodules do not shrink significantly within six months it is removed.

Treatment of hyperfunctioning thyroid nodules may include a liquid form of radioactive iodine, antithyroid drugs or surgical removal. The treatment is determined by the person's physical condition, age and by the nature and severity of the hyperthyroidism if present.

Surgery is recommended infrequently unless the nodules are greater than 4cm or if the nodule is indeterminate as to being benign or malignant.

Long term health problems may last for years. Some individuals may carry the nodule(s) throughout their lives. The nodules may be dormant for years before the individual experiences a health problem, such as an increase in the size of the nodule so that it becomes observable or causes pain due to the compression on the surrounding tissue, or interferes with swallowing or breathing. Hyperthyroidism may occur with nodular production of thyroid hormone. There are few reported instances in which benign/non malignant nodules became malignant.

Veterans who were exposed to ionizing radiation during their military service are eligible to participate, on a voluntary basis, in the VA's Ionizing Radiation Registry examination program. The registry offers continuous monitoring of eligible Veterans' health upon request.

• Consider service connection on a presumptive basis as a chronic condition (38 CFR §3.307; §3.309(a)).  

• Consider service connection on a presumptive basis as a condition associated with ionizing radiation exposure (38 CFR §3.307; §3.309(d); §3.311(b)).