Medullary carcinoma of the thyroid

From Ganfyd

This is an uncommon form of thyroid cancer deriving from the C-cell of the thyroid. It is classed as an APUD cell tumour. It commonly synthesises and secretes calcitonin (but no clinical effects are apparent in otherwise normal individuals). Other products, such as serotonin, may be secreted (leading to carcinoid syndrome.

Histology

• sheets of neoplastic cells
• hyaline stroma
• amyloid staining pattern

Spread

• local
• lymphatic
• haematogenous

Clinical features

History

• usually elderly
• 80% sporadic but may be part of MEN IIA/MEN IIB syndromes

Examination

• lump feels stony hard
  • due to infiltration of amyloid

Treatment

• thyroidectomy

Prognosis

• variable
  • surgery curative in absence if metastases
  • 50% 5-year survival in presence of metastases