Features of hyperthyroidism or hypothyroidism are not commonly seen in patients with thyroid malignancies as they rarely secrete thyroid hormones
| Type | Percentage | |
|---|---|---|
| Papillary | 70% | Often young females - excellent prognosis |
| Follicular | 20% | |
| Medullary | 5% | Cancer of parafollicular (C) cells, secrete calcitonin, part of MEN-2 |
| Anaplastic | 1% | Not responsive to treatment, can cause pressure symptoms |
| Lymphoma | Rare | Associated with Hashimoto's thyroiditis |
Management of papillary and follicular cancer
| Type | Notes |
|---|---|
| Papillary carcinoma | • 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 | |
| Follicular adenoma | • Usually present as a solitary thyroid nodule |
| • Malignancy can only be excluded on formal histological assessment | |
| Follicular carcinoma | • May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma. |
| • Vascular invasion predominates | |
| • Multifocal disease rare | |
| Medullary carcinoma | • 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. | |
| Anaplastic carcinoma | • Most common in elderly females |
| • Local invasion is a common feature | |
| • Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective. |