Endocrine tumours

Published on 09/04/2015 by admin

Filed under Hematology, Oncology and Palliative Medicine

Last modified 09/04/2015

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17 Endocrine tumours

Thyroid cancer

Thyroid malignancies are the commonest endocrine malignancy. Common types of thyroid cancers are papillary and follicular carcinomas (well-differentiated cancers) arising from epithelial cell, medullary carcinomas from the parafollicular C cells, anaplastic carcinoma and NHL. Well-differentiated cancers typically affect women in their 40s. The median age of presentation of medullary carcinoma is 50–60 years and older for anaplastic carcinoma.

Aetiology

The majority of thyroid cancers are sporadic. Other risk factors include radiation exposure (papillary carcinoma), genetic (e.g. MEN2 with medullary carcinoma, FAP with papillary carcinoma) and endemic goitre (follicular carcinoma).

Presentation

Common presentation is with an enlarging solitary nodule. Cervical lymphadenopathy is common with medullary, papillary and anaplastic carcinoma. Local invasion can lead to symptoms of hoarseness of the voice and dysphagia. Anaplastic carcinoma has an aggressive growth with local invasion and rapid growth which can lead to stridor.

Evaluation

Evaluation includes clinical examination and assessment for thyrotoxicosis which is rare in cancer. Initial investigations include thyroid function tests and FNA of the lesion. Biopsy may be indicated for lymphoma and anaplastic carcinoma and hemithyroidectomy is indicated for all follicular lesions. MRI is the preferred imaging to assess local invasion (Figure 17.1) as the use of iodine containing contrast can cause thyroid stunning which may prevent effective use of radioiodine for at least three months subsequently.

Figure 17.1 Axial (A) and coronal (B) view of MRI scan in anaplastic carcinoma of thyroid.

Staging

Box 17.1 shows the TNM staging system. The TNM and MACIS (Box 17.2) have been shown to be the best predictors of outcome in differentiated thyroid cancer.

Box 17.1
TNM staging in thyroid cancer

T stage

pT1	Tumour ≤2 cm in greatest dimension
pT2	Intrathyroidal tumour >2–4 cm in greatest dimension
pT3	Intrathyroidal tumour >4 cm in greatest dimension
pT4	Tumour beyond the thyroid capsule

N stage (cervical and upper mediastinal)

N0	No nodes involved
N1	Regional nodal involvement
	N1a Ipsilateral cervical nodes
	N1b Bilateral, midline or contralateral cervical nodes, or mediastinal nodes

Distant metastases

M0	No distant metastases
M1	Distant metastases
MX	Distant metastases cannot be assessed

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