The Management of Thyroid Nodules Flashcards
thyroid nodules are either
- solitary thyroid nodule
- multi nodular goitre
around how many solitary thyroid nodules are…
95% of all solitary thyroid nodules are benign
causes of benign solitary thyroid nodules
- cyst
- colloid nodules
- benign follicular adenoma
- hyperplastic nodule
what are the remaining solitary thyroid nodules
5% of solitary thyroid nodules are malignant
types of malignant thyroid carcinoma
- papillary
- follicular
- medullary
- anaplastic
- other
what is the most common type of malignant thyroid carcinoma
papillary which accounts for 80%
what are papillary and follicular thyroid carcinomas classified as
differentiated thyroid carcinomas
before you start investigating what should you make sure
that whatever your feeling is actually attached to the thyroid i.e. it should move up on swelling as the thyroid is invested by the pre tracheal fascia
what is an uncommon feature of a solitary thyroid nodule
pain and if it is painful then is usually caused by bleeding into a thyroglossal duct cyst
6 key steps when any person presents to you with a thyroid nodule
- 2 questions
- 2 examinations
- 2 investigations
2 questions you should ask
- have you ever been exposed to radiation?
- is there any family history of thyroid cancer?
2 examination findings
- is there any associated lymphadenopathy
- is there any associated hoarseness of voice
palpable lymph nodes along with a solitary thyroid nodule
is papillary cell carcinoma until proven otherwise as papillary cell carcinoma spreads lymphatically
if there is hoarseness of voice
suggests invasion into the recurrent laryngeal nerve and is probably caused by an aggressive type of thyroid carcinoma
2 investigations
- TSH level
- ultrasound guided fine needle aspirate (USFA)
benign thyroid nodules TSH level
usually have a low TSH and high T3 and T4 as they usually cantina functioning thyroid tissue
malignant thyroid nodules TSH level
usually have a normal TSH level excuse the nodule is non-functioning
ultrasound classifications
U1: normal (no nodule)
U2: benign
U3: indeterminate
U4: suspicious
U5: malignant
only what ultrasound classifications get a fine needle aspiration
U3-U5
fine needle aspiration classification
thy1: inadequate aspiration (redo it)
thy2: benign
thy3: atypical (all follicular lesions)
thy4: most likely malignant
thy5: malignant
thy 5 is diagnostic of
either papillary or medullary or anapaestic or lymphoma or metastatic tumour
management of differentiated thyroid cancers
first decide if the patient is low or high risk
low risk criteria for differentiated thyroid cancer
aged less than 50 and tumour is less than 4cm
management of low risk differentiated thyroid cancers
lobectomy
high risk criteria for thyroid cancer
agree greater than 50 and tumour is more than 4cm
management of high risk thyroid cancer
subtotal/ total thyroidectomy
post-surgery stratification for differentiated thyroid cancer using the
AMES SYSTEM
AMES SYSTEM
age
metastases
extension of primary tumour
size of primary tumour
in tayside the protocol for clearance of lymph nodes for differentiated thyroid cancer is as follows
- for papillary carcinoma the central compartment is cleared and the lateral compartment is sampled (and cleared if its spread)
- for follicular carcinoma the central compartment is cleared and the lateral compartment is left alone
post-surgery management f differentiated thyroid carcinomas
- start thyroxine treatment and monitor TSH levels surpassing them at the lower limit of normal
- monitor thyroglobulin as the 2 tumour are derived from follicular cells so produce thyroglobulin so it can be used as a tumour marker, as post-surgery thyroglobulin levels should be negligible
papillary carcinoma
most common type of thyroid cancer accounting for 80% and has the best prognosis
papillary carcinoma is more common in
3x more common in females
histology of papillary carcinoma
no capsule and nuclei appear empty (known as ORPHAN ANNIE EYE)
papillary carcinomas are derived from
follicular cells and spread via the lymph nodes
papillary carcinoma is more common in those with
RET AND BRAF MUTATIONS and if you’ve been exposed to radiation as a child
papillary cell carcinoma secretes
thyroglobulin and takes up radio iodine
follicular carcinoma accounts for
10% of thyroid carcinomas
follicular carcinomas are most common in who
3x more common in females
follicular carcinomas are derived from
follicular cells and spread haematogenously
increased risk of follicular carcinoma in those with
RAS mutations
histology of follicular carcinomas
surround by a capsule
if the capsule is intact then by definition it is a
benign follicular adenoma
if the capsule is not intact then by definition it is a
follicular carcinoma
what can you not tell from fine needle aspiration which is relevant to follicular cell carcinoma
whether the capsule is intact or not so can only be seen when examined post-surgery
follicular cell carcinoma is classified as
minimally invasive thyroid carcinoma or widely invasive
follicular cell carincomas secrete
thyroglobulin and take up radioactive iodine
medullary thyroid carcinoma accounts for
3% of all thyroid carcinomas and is more aggressive than the 2 differentiated types
medially thyroid cancer is derived from
parafollicualr C cells so secreted calcitonin which can be used as a tumour marker
on histology of medullary thyroid carcinomas
stroma is made of AMYLOID
4 TYPES of medullary thyroid carcinoma
- sporadic MTC
- familial MTC
- MEN2a
- MEN2b
familial thyroid carcinoma, MEN2a and MEN2b are all used by
defects on RET genes on chromosome 10
MEN2a
- MEDULALRY THYROID CARCINOMA
- PHAEOCHROMOCYTOMA
- HYPERPARATHYROIDISM
IS MEN2A IS KNOWN ABOUT WHAT IS CARRIED OUT
a prophylactic thyroidectomy while young
MEN2b
- medullary thyroid carcinoma
- pheochromocytoma
- hyperparathyroidism
- nueromas
about MEN2b
probably never see in practise as they allude very young of aggressive medullary thyroid carcinoma
anaplatic carcinomas known as
undifferentiated thyroid carcinomas
anaplatic carcinomas mostly affects
the elderly and are deadly
