-IBIS-1.5.0-
tx
endocrine system
thyroid cancer
diagnoses

definition and etiology

definition: Neoplasm of the thyroid.

etiology: There are five types of thyroid tumor: most are found by the asymptomatic patient or physician during routine palpation of the gland: papillary, follicular, mixed (most common), medullary, and anaplastic (rare). These factors are implicated in a patient developing a thyroid tumor:
• Age: Usually occurs in young people.
• Sex: Since women have more thyroid disease then men, male patients with thyroid nodules raise the index of suspicion.
• Amount of lesions: A solitary lesion is more suspicious as multiple lesions usually indicate multinodular goiter.
• RAI uptake scan: A cold nodule is usually malignant; cancer rarely shows as a hot nodule.
• X-ray findings: Indicative of medullary or papillary cancer.
• Consistency: Malignant nodules appear "stony-hard".
• Pertinent history: such as radiation to the head, neck, or chest.

Description of the three commonly seen types:
• Papillary: the most commonly seen thyroid cancer, it is found 2-3 times more often in women than in men. Although seen more frequently in the young, it is a more serious malignancy in the senior citizen. It is often seen in patients who have had radiation exposure or Hashimoto's thyroiditis.

• Follicular: responsible for approximately 25% of thyroid tumors and is seen more often in the elderly patient. It also is more common in females and has a history of radiation associated with its onset. As follicular cancer spreads through the blood, it more easily causes distant metastases and is therefore more malignant.

• Medullary: usually seen in patients over 15 in either a sporadic form (typically unilateral) or with a familial association (typically bilateral). If associated with pheochromocytoma (in 50-75% of patients) and hyperparathyroidism (in 50% of patients), then is it known as Sipple's syndrome.

signs and symptoms

• Thyroid nodule typically found on routine palpation.

lab findings:
• RAI reveals cold nodule.
• X-rays show homogenous calcification.
• Excess of calcitonin: in medullary cancer.
• Increased histamine levels: seen in 50% of patients, but not specific to thyroid disease.
• May be hyperthyroid.

course and prognosis

Conventional treatment is generally thyroidectomy followed by lifelong replacement therapy with synthetic thyroid hormone. Survival rate is good.

differential diagnosis

• Goiter.
• Cyst.


footnotes