Anaplastic carcinoma - Malignant tumours of the thyroid

Anaplastic carcinoma

Definition

This is a highly malignant tumour of the thyroid.

Incidence/prevalence

10–15% of cases of malignant tumours of the thyroid.

Pathophysiology

There is evidence that these are poorly differentiated adenocarcinomas derived from thyroid epithelium. They often arise in elderly patients with a long history of goitre in whom the gland suddenly enlarges.

Clinical features

These tumours are rapidly growing and invade local structures early, most patients present with a rapidly enlarging neck swelling and complications such as hoarseness, dyspnoea and stridor, dysphagia and Horner’s syndrome (miosis, partial ptosis and anhydrosis).

Macroscopy/microscopy

Diffusely infiltrative mass, often invading neighbouring tissues. Composed of various undifferentiated cells.

Management

Resection is rarely possible, but may be carried out for palliative relief of tracheal compression. Radioactive iodine and radiotherapy are ineffective.

Prognosis

Poor: 1-year survival is âˆ¼30%.