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 raree | |
| 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. |
Neoplasia of the Thyroid
the most common adenoma >> follicular (highly differentiated, autonomous),
other forms include papillary and Hürthle
Note:
An activating missense mutation in codon 600 of exon 15 (V600E) of BRAF gene has been identified in multiple neoplasms including melanoma, colorectal carcinoma, papillary thyroid carcinoma, hairy cell leukemia, and Langerhans cell histiocytosis.
Ca Thyroid (never hyperfunctioning)
Papillary is the most common (60-70%)
asso: w/ h/o radiation exposure