Thyroid Cancer

Last updated:

Overview

Thyroid cancers are the most common endocrine malignancy. In general, differentiated tumours (papillary or follicular) are more treatable and usually curable, and poorly-differentiated tumours (medullary or anaplastic) are more aggressive and have a poorer prognosis. This section will cover surface-level detail of thyroid cancers.

To help make sense of this chapter, it may be helpful to refer to Endocrine and Metabolic Physiology.

Types

  • Papillary thyroid carcinoma:
    • Most common form of thyroid cancer – around 70%
    • More common in women aged 35-40 years
    • Metastases tend to spread locally in the neck
    • The prognosis is excellent
  • Follicular thyroid carcinoma:
    • Second most common form of thyroid cancer – around 10%
    • May infiltrate the neck but tends to metastasise to the lung and bones
    • More common in women aged 30-60 years
  • Medullary thyroid cancer:
    • Cancer of parafollicular calcitonin-producing C cells of the thyroid
    • Can be sporadic, but can be inherited as part of multiple endocrine neoplasia (MEN) 2A or 2B
    • Serum calcitonin is often raised
  • Anaplastic thyroid cancer:
    • One of the most aggressive cancers in humans
    • Most common in people aged 55-65 years of age
    • Usually infiltrates the neck leading to compression (cough, vocal cord paralysis, dysphagia, dyspnoea etc.)
    • Mean survival is often <6 months, regardless of treatments given
  • Thyroid lymphoma:
    • Associated with Hashimoto’s thyroiditis
    • More common in women around the age of 65 years
    • Usually a rapidly growing mass in the neck which can lead to symptoms due to compression

Investigations

  • TFTs:
    • Usually normal
  • Neck ultrasound:
    • Shows masses/nodules
    • Features seen include macrocalcifications, irregular borders, intramodular blood flow, and peripheral halo
  • Fine-needle aspiration cytology (FNAC):
    • Allows for histological diagnosis
  • Radioactive iodine uptake testing:
    • ‘Cold areas’ are areas of abnormally low uptake and are seen in thyroid cancer

Management

  • Options involve a total thyroidectomy, radioactive iodine, and radiotherapy.

Author