Thyroid Nodules

Thyroid nodule is a small mass of tissue or lump associated with the normal thyroid gland. The abnormal growth of fibroid tissues forms nodules in the thyroid gland. The growth of the nodules may be benign or carcinogenic. But more than 96% of the nodules are non carcinogenic.

Description:
The Thyroid gland is situated at the base of the neck below 'Adam's apple'. It is butterfly shaped and located in front of the neck. The two thyroid lobes on either side of the wind pipe is connected by a tissue called 'isthmus' which covers the wind pipe from the front side.

Thyroid nodule can develop on any part of the gland. Abnormal growth of thyroid gland or excess growth of tissues leads to the formation of lumps. Mostly, these lumps are fluid filled and benign. When the nodule becomes large enough to compress the wind pipe, the person may feel difficulty in swallowing.

Five percent of the thyroid nodules are cancers or may lead to cancers.

Causes:
The various causes for the occurrences of thyroid nodules are

• Deficiency of iodine
• Thyroxin is suppressed due to physical agents
• Chronic thyroditis-condition due to hypothyroidism.

Men are more likely to be affected by carcinogenic thyroid nodules. Continuous exposure of radiation to the head or neck causes carcinogenic nodule.

Types of Thyroid Nodules:
There are seven types of nodules which are listed below;

Colloid nodules or Follicular adenoma: They are nothing but the overgrowth of thyroid gland which are non cancerous. Only single lobe is formed and does not exceed beyond the thyroid gland. Hence it is harmless.

Thyroid cysts: These are nodules of 1-1.5 cm in diameter and filled with fluid. Sometimes they are malignant and filled with solid substances also.

Inflammatory nodules: They occur as the result of thyroiditis i.e. chronic inflammation of the thyroid gland. One of the types is subacute thyroiditis which causes severe pain in the neck region.

Thyroid cancer: They are malignant, very large lobes and hard which causes discomfort in the neck region.

Multinodular goiter: Goiter which contains multiple nodes and each node may be benign or malignant.

Toxic multinodular goiter-Plummer's disease: In this case, the thyroid gland secretes thyroxin without the influence of thyroid stimulating hormone which is supposed to stimulate. High levels of thyroxin in the blood results in high metabolism rate in the body.

Symptoms:
The normal symptoms of thyroid nodules are

• Pain in the neck region.
• Difficulty in swallowing.
• Sudden weight loss.
• Irregular heartbeat.
• Hoarseness i.e. difficulty in speaking.
• Enlargement of lymph nodes in the neck region.

Effects:
Though the thyroid nodule is benign, it creates critical complications. Some of them are

• Heart problems which include rapid heart rate, irregular heartbeat and the heart's muscles become weak to pump the blood to various parts of the body.
• Osteoporosis which include weakened and brittle bones due to lack of sufficient amount of calcium in the body. This is due to the improper secretion of calcitonin by thyroid gland.
• Thyrotoxis problem which is life-threatening.

Treatment:
The common treatments for thyroid nodules are listed below;

• Using radioactive iodine will reduce the size of goiter but the radiation induced therapy may result in side effects. Pregnant women should not undergo this treatment.
• Under conditions when the nodule compresses the wind pipe, doctors prescribe a drug called Levothyroxine which is used for the immediate suppression of the production of thyroxin. This is called thyroid hormone suppression therapy.
• In Alcohol Ablation, ethanol is used to compress the nodules and reduces the excess secretion of thyroxin hormone.

When the nodules are cancerous, surgery is the only remedy.