Different problems of thyroid gland

Thyroid nodules are lumps which commonly arise within an otherwise normal thyroid gland. They indicate a thyroid neoplasm (abnormal growth of tissue), but only a small percentage of these are thyroid cancers.

Often these abnormal growths of thyroid tissue are located at the edge of the thyroid gland and can be felt as a lump in the throat. When they are large or when they occur in very thin individuals, they can sometimes be seen as a lump in front of the neck.

Sometimes a thyroid nodule presents as a fluid filled cavity called a thyroid cyst. Often, solid components are mixed with the fluid. Thyroid cysts most commonly result from degenerating thyroid adenomas, which are benign, but they occasionally contain malignant solid components.

After a nodule is found during a physical examination, most commonly an ultrasound is performed to confirm the presence of a nodule, and assess the status of the whole gland. Measurement of thyroid stimulating hormone and anti-thyroid anti-bodies will help decide if there is a functional thyroid disease such as Hashimoto's Thyroiditis present, a known cause of a benign nodular goiter. Fine needle biopsy for histopathology is also used.

Thyroid nodules are extremely common in young adults and children. Only a small percentage of lumps in the neck are malignant (around 4-6.5% ), and most thyroid nodules are benign.

There are many factors to consider when diagnosing a malignant lump. Trouble swelling or speaking, swollen cervical lymph nodes or a firm, immobile nodule are more indicative of malignancy, whereas a family history of autoimmune disease or goiter, thyroid hormonal dysfunction or a soft, painful nodule are more indicative of benignancy.

The prevalence of cancer is higher in males, patients under 20 years old or over 70 years old, and patients with a history of head and neck irradiation or a family history of thyroid cancer.

Solitary thyroid nodules are more common in females yet more worrisome in males. Other associations with neoplastic nodules are family history of thyroid cancer and prior radiation to the head and neck.

Radiation exposure to the head and neck may be for Hodgkin's lymphoma. Thyroid cancer arising in the background of radiation is often multifocal with a high incidence of lymph node metastasis and has a poor prognosis.

Worrisome signs and symptoms include voice hoarseness, rapid increase in size, compressive symptoms (such as dyspnoea or Dysphagia) and appearance of lymphadenopathy.

If you experience any of these symptoms, don't panic, but consult a specialist physician to rule out any worst case scenario.

The write-up is compiled by Dr A K M Aminul Hoque, Prof of Medicine at Dhaka Community Medical College & Hospital.