50.1 Epidemiology

• Incidence

4 to 7% population (autopsies suggest prevalence as high as 40 to 70% of population)

5 to 10% malignant

• Incidentalomas

A nonpalpable nodule detected on imaging

Same risk of malignancy as palpable

1 to 2% incidence of “PETomas” (33% risk malignancy)

Diffuse positron emission tomography uptake: thyroiditis

• Malignant risk factors

History irradiation or exposure to radioactive material

Family history thyroid cancer

Age <20 or >70 years

Familial adenomatous polyposis

Cowden syndrome (macrocephaly, mild learning difficulties, carpet-pile tongue, benign or malignant breast disease)

Sex: male

Vocal cord palsy

Fixation to surrounding structures

Cervical lymph nodes

50.2 Investigations

• Serum thyroid stimulating hormone (thyroglobulin and calcitonin levels are not