Skip to main content

Table 1 Risk factors for thyroid malignancy. Baseline UK annual incidence for thyroid cancer: 2 - 3/100,000 population [3].

From: Management of Thyroid nodules in adult patients

Risk factors Risk of malignancy
Gender [4, 9] Male: 2 - 3 times increased risk.
Age [4, 8] Less than 20: Risk of malignancy doubled.
Above age 45: Increased risk of malignancy.
Above 70: Risk of malignancy quadrupled.
Ionising radiation [3, 10] Latency period is usually 10 - 15 years and mostly occurs 20 - 30 years after exposure.
  There is a 40% absolute risk of malignancy for a thyroid nodule in a patient with previous radiation exposure [9].
  Low dose: 100 times increase risk of malignancy (lifetime risk).
  High dose: 300 times increase risk of malignancy (lifetime risk).
Family history [3] Presence of thyroid cancer in family members increases risk of malignancy.
Tumour size [4, 11] The larger the tumour size, especially when >4 cm, or the presence of obstructive symptoms indicates higher risk of malignancy.
Rate of growth [3, 10, 11] History of rapid growth in a few weeks indicates higher risk of malignancy.
Hoarse voice or vocal cord palsy with recurrent laryngeal nerve involvement [11] Presence of hoarse voice or vocal cord palsy indicates high risk of malignancy.
Cervical lymphadenopathy [11] Presence of cervical lymphadenopathy indicates high risk of malignancy.
Characteristics of thyroid swelling [11] Firm/hard consistency or fixed swelling indicates high risk of malignancy.
Soft, mobile or cystic swelling indicates low risk of malignancy.