Thyroid Neoplasms

Question 1

Follicular adenoma

Answer 1

Usually present as a solitary thyroid nodule

Malignancy can only be excluded on formal histological assessment

Question 2

Papillary carcinoma

Answer 2

Usually contain a mixture of papillary and colloidal filled follicles
Histologically tumour has papillary projections and pale empty nuclei
Seldom encapsulated
Lymph node metastasis predominate
Haematogenous metastasis rare
Account for 60% of thyroid cancers

Question 3

Follicular carcinoma

Answer 3

May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma.
Vascular invasion predominates
Multifocal disease rare
Account for 20% of all thyroid cancers
Elevated thyroglobulin levels raises suspicion of recurrence

Question 4

Anaplastic carcinoma

Answer 4

Most common in elderly females
Local invasion is a common feature
Account for 10% of thyroid cancers
Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective.

Question 5

Medullary carcinoma

Answer 5

Tumours of the parafollicular cells (C Cells)
C cells derived from neural crest and not thyroid tissue
Serum calcitonin levels often raised
Familial genetic disease accounts for up to 20% cases
Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis