Thyroid Nodules Flashcards
What are the two types of thyroid nodule?
Solitary thyroid nodule
Multi-nodular goitre
Are there more benign or malignant thyroid nodules?
95% benign
What are the types of benign solitary thyroid nodules?
Thyroid cyst
Colloid nodule
Benign follicular adenoma
Hyperplastic nodule
What are the types of malignant solitary thyroid nodules?
Papillary thyroid carcinoma Follicular thyroid carcinoma Medullary thyroid carcinoma Lymphoma Anaplastic thyroid carcinoma
How would you tell if a nodule in the neck is in the thyroid or not?
Ask patient to swallow - if it moves it is in the thyroid
Pain is uncommon in thyroid nodules
What is pain usually caused by if present in a thyroid nodule?
Intra-thyroidal bleed into a cyst
What are risk factors for thyroid carcinomas?
Neck irradiation
Family history
What are the signs and symptoms of thyroid carcinomas?
Nodule in neck
Hoarseness
Enlarged cervical lymph nodes
What investigation is done for suspected thyroid carcinoma?
TSH levels
Ultrasound guided fine needle aspiration
May need core biopsy for lymphoma
What are the FNA classifications and what likelihood of carcinoma do they indicate?
Thy1 - inadequate sampling Thy2 - benign Thy3 - atypical, more investigation needed Thy4 - probably malignant Thy5 - malignant
What factors indicate low risk of malignancy?
Aged <50
Tumour <4cm
TSH lower range of normal, baseline thyroglobulin
What factors indicate high risk of malignancy?
Aged >50
Tumour >4cm
TSH <1
What is the treatment for low risk patients?
Thyroid lobectomy
What is the treatment for high risk patients?
Total thyroidectomy
Consider radioactive iodine
In follow up of differentiated thyroid cancer, what substances should be at what level?
TSH - keep at lower end ofnkormal (0.4-4)
Thyroglobulin - keep low
What can be an indication of recurrence of thyroid caner?
Rising levels of thyroglobulin
What is a risk factor for thyroid lymphoma?
Background of autoimmune hypothyroidism
What is the usual presentation of a thyroid lymphoma?
Rapid onset of mass in the thyroid
What is the treatment for thyroid lymphoma?
Steroids
Chemotherapy
Radiotherapy
What is medullary thyroid carcinoma?
A tumour of the parafollicular cells
What is the tumour cell marker for medullary thyroid carcinomas?
Calcitonin (the substance c cells secrete)
What are the types of medullary thyroid carcinoma?
Sporadic
Familial non-MEN
MEN
MEN2a
What is MEN2a medullary thyroid carcinoma associated with?
Phaeochromocytoma
Hyperparathyroidism
Mucosal neuromas
How can multi-nodular goitres function?
Over or underactive
Toxic
What symptoms can be caused by compression of structures by a multi-nodular goitre?
Stridor
Chocking lying flat
What are TSH levels in multi-nodular goitres?
Usually normal or slightly suppressed
What signs of a multi-nodular goitre can be seen on CT scan?
Retrosternal extension
Tracheal compression
What is the treatment for multi-nodular goitre?
Most can be left alone
Radioactive iodine if significant hyperthyroidism
Surgery if structural problem
What are indications for surgery for multi-nodular goitre?
Lifestyle interfering symptoms
Possibility of cancer
Significant tracheal compression
What are the two most common thyroid carcinomas?
Papillary (76%)
Follicular (17%)
What does ‘differentiated thyroid carcinoma’ (DTC) refer to?
Papillary and follicular carcinomas
Both well differentiated and look very similar to normal histology
How do DTCs function?
Take up iodine and secrete thyroglobulin
What is the prognosis like for DTCs?
Very good
What are risk factors for DTCs?
Exposure to radiation
No other strong associations
What is the usual presentation of DTCs?
Palpable nodules
Some are incidental findings
How do papillary thyroid cancers spread?
Lymphatics
Can spread by haematogenous spread to lungs, brain, liver, bone
What condition is papillary thyroid cancer associated with?
Hashimoto’s thyroiditis (autoimmune hypothyroidism)
How do follicular thyroid cancers spread?
Haematogenous route
Lymphatic spread is rare
What are the surgical options for thyroid cancer?
Thyroid lobectomy with isthumectomy
Sub-total thyroidectomy
Total thyroidectomy
What is the post-operative care for thyroid cancer?
Check calcium within 24 hours
Start calcium replacement if it falls below 2mmol/l
Discharge on T3 or T4
When is whole body iodine scanning done?
In patients who have undergone sub-total or total thyroidectomy
What is done before whole body iodine scanning and why?
TSH levels are raised with synthetic TSH to ensure sensitivity of the thyroid to iodine
What is the purpose of whole body iodine scanning?
Will show any areas of thyroid cancer activity
What is thyroid remnant ablation?
A treatment for thyroid cancer involving radiation that can ablate residual thyroid tissue to destroy microfoci that surgeons can’t see
What are the side effects of thyroid remnant ablation?
Siladenitis (painful salivary glands)
Sore throat
