Management of Thyroid Nodules Flashcards
How common are solitary thyroid nodules?
Very = affect 5% of women, 95% are benign
What are examples of benign solitary thyroid nodules?
Cysts, colloid nodule, follicular adenoma, hyperplastic nodule
What are examples of malignant solitary thyroid nodules?
Papillary carcinoma (80%), follicular carcinoma, medullary thyroid carcinoma, lymphoma
What criteria are used to classify thyroid nodules?
U classification (U2-5) FNA Bethseda classification (Thy1-5)
What can be used to investigate thyroid nodules?
Ultrasound fine needle aspiration Core biopsy (for lymphoma)
What is the grading of solitary thyroid nodules?
Thy1 = inadequate Thy2 = benign (U2) Thy3 = atypical (U3) Thy4 = probably malignant (U4) Thy5 = malignant (U5)
What is the low risk group for differentiated thyroid cancer?
Age <50, tumour <4cm
Get baseline Tg, TSH loser range, may need lobectomy
What are some features of differentiated thyroid cancer?
Treated with total thyroidectomy, TSH <1mU/L, Tg measurement
What are some scoring systems for differentiated thyroid cancer?
AMES, AGES, MACIS, TMN
What are the T stages of the TMN staging?
T1 = tumour size <= 2cm T2 = tumour size >2cm but <=4cm, limited to thyroid T3 = tumour size >4cm, limited to thyroid or any tumour with minimal extrathyroidal extension T4a = moderately advanced disease, tumour of any size extending beyond thyroid capsule into nearby soft tissue T4b = very advanced disease, tumour invades prevertebral fascia or encases carotid arteries/mediastinal vessels
What are the N stages of the TNM staging?
N0 = no regional lymph node metastases N1 = regional lymph node metastases: N1a = metastases to level VI N1b = metastases to unilateral, bilateral or contralateral cervical, or retropharyngeal or superior mediastinal lymph nodes
What are the M stages of the TNM staging?
M0 = no distant metastases M1 = distant metastases
At what vertebral level is the central neck?
Level C6-7
At what vertebral level is the lateral neck?
Level C2-5
How is low risk differentiated thyroid cancer treated?
Thyroid lobectomy
How is high risk (T3 or higher) differentiated thyroid cancer treated?
Total thyroidectomy, radioactive iodine
What is thyroglobulin?
Protein precursor of T3/4, made by thyroid follicular epithelial cells, used as tumour cell marker for follow up
What is the follow up for patients who have been treated with differentiated thyroid cancer?
TSH low (0.4-4mU/L) Get TSH/Tg measured every 6 months for first five years then annually for next five years
When can low risk differentiated thyroid cancer patients who have been treated stop follow up appointments?
After five years
What does diagnosis of follicular carcinoma depend on?
Invasion of capsule or vascular invasion
Classified as minimally or widely invasive
What are some features of follicular carcinomas?
Haematogenous spread
Uncommon to have disease
What are some features of minimally invasive follicular carcinomas?
Most common type
Most present with U3 Thy3 lesion and diagnosed on diagnostic lobectomy
Can’t tell if capsular invasion on FNA
How are minimally invasive follicular carcinomas treated?
Usually treated with thyroid lobectomy
If significant vascular invasion consider total thyroidectomy
What are some features of thyroid lymphomas?
Background of autoimmune hypothyroidism (on T4)’ rapid onset of mass in thyroid, most commonly women aged 70-80
How are thyroid lymphomas diagnosed and treated?
Core biopsy for histology diagnosis
Chemo (R-CHOP), DXT or steroids
What are the types of medullary thyroid carcinomas?
Sporadic, familial non-MEN, familial MEN (MEN2a)
What should always be checked in suspected medullary thyroid carcinoma?
24hr urinary metanephrine and genetics
What can MEN2a mutations cause?
Medullary thyroid carcinoma, phaechromocytoma, hyperparathyroidism
Consider prophylactic thyroidectomy in child
What should be assessed in multinodular goitres?
Assess function and structure
What is TSH like in multinodular goitres?
Usually normal or slightly suppressed, occasionally need antithyroid drugs
What do CT scans of multinodular goitres show?
Retrosternal extension, tracheal compression
How are multinodular goitres treated?
Most can leave alone
RAI if significant hyperthyroid
Surgery if structural problem or significant retrosternal extension
When is surgery offered to patients with retrosternal goitres?
Lifestyle interfering symptoms, possible cancer, significant tracheal compression if symptomatic, tracheal flow loops if other respiratory causes of orthopnoea, audible stridor
