Performing an ultrasound guided fine needle aspiration (FNA) is crucial for distinguishing between benign and malignant thyroid masses. The results are usually expressed using the THY cytology grading system, which ranges from non-diagnostic (THY1) to diagnostic of malignancy (THY5). Additional useful investigations include thyroid function tests to rule out hyper or hypothyroid conditions, as any mass with euthyroid biochemistry should be suspected as cancer. Together, FNA cytology and thyroid function tests help establish the diagnosis prior to further management.

1. THYROID CANCER
THE MEDICAL STUDENTS AND FOUNDATION DOCTORS GUIDE TO
THYROID CANCER AND THE DIFFERENTIAL DIAGNOSIS OF
LUMPS IN THE NECK
ADAM BEEBEEJAUN
FOURTH YEAR MEDICAL STUDENT
PENINSULA MEDICAL SCHOOL 2010

2. Contents Page
Introduction 1
Anatomy of Thyroid Gland 2
Function of Thyroid Gland 4
Checkpoint 1 5
Thyroid Cancer Overview 6
Epidemiology, Aetiology & Risk Factors & Checkpoint 2 7
Clinical Features 8
Investigations 9
Staging & Checkpoint 3 10
Management 12
Complications 14
Follow Up 15
Prognosis, Differential Diagnosis of Neck Lumps & Checkpoint 4 16
Checkpoint 5 18
Answers to Checkpoints 19
Summary of Thyroid Cancer 20
Further Reading 21

3. Acknowledgements
I would like to take this opportunity to thank the following people for their invaluable support
and guidance throughout the construction and development of this learning resource:
Dr Andrea Hodgkinson, Lecturer in Biomedical Sciences at Peninsula Medical School for her
vital support and for putting up with the multiple meetings to discuss the resource.
Mr Simon Hickey, Consultant ENT Surgeon at Torbay Hospital for proof-reading the
resource and making helpful amendments.
Dr Amy Roy, Consultant Oncologist at Derriford Hospital for proof-reading the resource,
providing invaluable feedback, and providing fantastic learning opportunities which were the
inspiration for this resource.
Dr Sarah Pascoe, Consultant Oncologist at Derriford Hospital for critiquing my resource and
suggesting several improvements to the resource despite her intense work schedule.
Dr Sarah Owens, ENT Senior House Officer at Derriford Hospital for proof-reading the
resource, especially since it was done over the Christmas holidays.
Mr Vikas Acharya & Mr Kuljinder Klear, Fifth and Third Year Medical Students at Peninsula
Medical School for proof-reading all the versions of the resource and for their insights into
the fundamental structure and design of the resource.
Miss Katie Marsden, a qualified teacher with Colegio Luso Internacion de Braga, who proof-
read the resource, and put all my worries and concerns into perspective.
Mr Sowkatally Beebeejaun, Senior Lecturer at DeMontfort University, for proof-reading
multiple copies of the resource, providing feedback on all aspects of the resource and
providing love and support that only a father could.
Mr Paul Russell, PCMD E-Learning Officer, for giving me advice regarding copyright issues.
Finally, a big thank you to all the medical students and foundation doctors who assisted in
the research and development of this learning resource.

4. 1
Introduction
Cancer has a reputation amongst patients as being a ‘death sentence.’ As a medical
student, it can be a challenging experience when you see a patient suffering from any form
of cancer. Thyroid cancer is one of the many areas of oncology that is not covered directly in
the medical school curriculum. As a result I decided to create a booklet to help students
understand the key concepts relating to thyroid cancer for applied clinical knowledge exams
and be of assistance in clinical practice.
This booklet should hopefully give the reader an overview of anatomy and physiology of the
thyroid gland, the diagnosis and management of thyroid cancers. It is important to
understand that background reading is essential to help underpin basic science to clinical
scenarios. Many conditions can present as lump(s) in the neck, but the purpose of this
resource is to focus solely on thyroid cancers.
Should you have any questions or would like any further information on this resource please
do not hesitate to contact me.
Kindest Regards,
Adam Beebeejaun (Fourth Year Medical Student, Plymouth)
Doctors as Teachers SSU 2010/11
adam.beebeejaun@students.pms.ac.uk
Thyroid Examination

5. 2
Anatomy of the Thyroid Gland
The thyroid gland is one of the largest endocrine organs in the body and is located in the
midline of the neck between the levels of C5 and T1. It is situated anterolateral to the
trachea and larynx, inferior to the thyroid cartilage and is approximately at the same level as
the cricoid cartilage.
The gland is ‘butterfly-shaped’ with a right and left lateral lobe on either side of the trachea
connected by an isthmus, situated anteriorly to the 2nd
and 3rd
tracheal rings. The gland is
surrounded by a thin fibrous capsule which attaches to the cricoid cartilage and superior
tracheal rings by dense connective tissue (figure 1).
Most of the thyroid gland is made up of follicular cells which produce the two main thyroid
hormones – triiodothyronine (T3) and thyroxine (T4).
Arterial Supply
The thyroid gland is supplied by two pairs of arteries: the superior and inferior thyroid
arteries. The anterior and superior aspects of the gland are supplied by the superior thyroid
arteries which are branches of the external carotid arteries.
The inferior thyroid arteries are branches of the subclavian arteries. They divide into several
branches which supply the posterior and inferior aspects of the thyroid gland.
The right and left superior and inferior thyroid arteries anastomose extensively within the
gland, ensuring its blood supply and also providing a potential collateral circulation between
the subclavian and external carotid arteries (figure 2).
Figure 1 Figure 2

6. 3
Venous Drainage
The venous drainage of the thyroid gland is composed of three pairs of veins forming a
plexus of veins on the anterior surface of the thyroid gland. These are the superior, middle
and inferior thyroid veins (figure 3).
The superior thyroid veins accompany the superior thyroid arteries and drain the superior
poles. The middle thyroid veins run parallel to the inferior thyroid arteries and drain the
middle lobes. Both the middle and superior thyroid veins drain into the internal jugular veins.
The inferior thyroid veins collect blood from the inferior poles and drain into the
brachiocephalic veins. It is important to understand the venous drainage as it is directly
related to haematological spread of thyroid cancer.
Innervation
The thyroid gland is innervated by the cervical sympathetic ganglia (figure 3). These fibres
are vasomotor in nature and therefore cause constriction of blood vessels. Endocrine
functions are exclusively hormonally controlled by the pituitary gland.
Lymphatic Drainage
The lymphatic vessels of the thyroid gland pass through the prelaryngeal, pretracheal and
paratracheal nodes into the superior and inferior deep cervical nodes. These vessels
terminate in either the brachiocephalic lymph node or thoracic duct. Knowledge of the
lymphatic drainage allows one to understand the lymphatic spread of thyroid cancer (figure
3).
Figure 3

7. 4
Function of the Thyroid Gland
The thyroid gland is an endocrine gland which has several effects throughout the body:
1. The primary function is to increase basal metabolic rate (BMR) which promotes the
metabolism of carbohydrates, lipids and proteins (and oxygen) to produce
adenosine-5’-triphosphate (ATP).
2. Produce more sodium-potassium pumps (Na+/K+/ATPase) which require more ATP.
This extra energy demand can raise the body temperature (calorigenic effect). In this
way, thyroid hormones significantly contribute to the maintenance of normal
temperature (even in cold conditions).
3. Enhance the action of certain catecholamines (noradrenaline and adrenaline).
4. Together with human growth factor and insulin, thyroid hormones accelerate growth
of nervous and skeletal tissue in utero, infancy and childhood.
Secretion of the thyroid hormones and their negative feedback is controlled through
hormones secreted from the hypothalamus and pituitary gland (figure 4).
HYPOTHALAMUS
ANTERIOR PITUITARY
GLAND
THYROID GLAND
(FOLLICLE)
T3 & T4 release into bloodstream
TRH
TSH
Low blood levels of T3 and T4
or low BMR stimulates
hypothalamus to produce
TRH
TRH, carried to the anterior
pituitary which stimulates the
production of TSH
TSH released into the blood
stimulates the follicular cells of
the thyroid gland to produce T3
and T4 into the bloodstream.
Elevated levels of T3 inhibits
release of TRH and TSH
(negative feedback)
Figure 4

8. 5
Calcitonin is the other hormone produced by the parafollicular cells of the thyroid gland.
Calcitonin reduces the serum calcium level by inhibiting the action of osteoclasts (cells that
breakdown the bone extracellular matrix). The levels of calcitonin are controlled by negative
feedback (figure 5).
THYROID GLAND
(Parafollicular Cells)
Reduction in Ca2+
in the blood
Calcitonin Produced
Low levels of Ca2+
CHECKPOINT 1
1. What is the anatomical location of the thyroid gland?
2. Which are the two main hormones produced by the thyroid gland and how are
they regulated?
3. What are the functions of thyroid hormones?
4. What vessel(s) supply the inferior and superior thyroid arteries?
5. Which thyroid vessels drain into the internal jugular veins and brachiocephalic
veins?
Figure 5

9. 6
Thyroid Cancer
Thyroid cancer is different from other cancers in a variety of ways. Most thyroid cancers are
very indolent with a long natural history, often over many decades, even if complete tumour
control has not been achieved. Thyroid cancers have four distinct pathologies: papillary,
follicular, medullary and anaplastic.
 Papillary Carcinoma
This is the most common type of thyroid cancer comprising approximately 70% of all
thyroid cancers. Its peak incidence is 35 – 40 years of age and is 3 times more common
in women. It tends to spread locally in the neck, compressing the trachea and possibly
the recurrent laryngeal nerve via the lymphatic system. Rarely papillary carcinomas can
metastasise to the lung and bone. Papillary carcinoma is a well differentiated cancer
meaning the cancer cells retain the characteristics of thyroid tissue.
 Follicular Carcinoma
This is the second most common form of thyroid cancer (10%) and tends to occur in
areas of low iodine. It also has a slight female predominance but a higher mean age of
incidence (30 – 60 years). Follicular carcinomas have a higher propensity to metastasise
to the lung and bone as opposed to local neck invasion. Its main route of dissemination
is haematogenous; therefore lymph nodes are rarely involved. As with the papillary type,
follicular cancer is a well differentiated carcinoma.
 Medullary Carcinoma
Medullary carcinomas, an intermediately differentiated cancer, represent approximately
5% of thyroid cancers and originate from the parafollicular cells (C-cells) which produce
calcitonin. 25% of medullary thyroid cancers are genetic in origin, caused by a mutation
in the receptor tyrosine kinase (RET) proto-oncogene on chromosome 10. Typically this
form of cancer can show an amyloid (fibrous protein aggregates) appearance, and it has
a high metastatic potential to the lymph nodes and blood stream. This condition is also
associated with Multiple Endocrine Neoplasia (MEN) syndrome type 2.
 Anaplastic Carcinoma
Anaplastic carcinoma of the thyroid represents 2% of all thyroid cancers and is
predominant form in the elderly population. It is a very aggressive and poorly
differentiated cancer and over 50% of patients have metastases at presentation. The
prognosis is very poor in patients with anaplastic disease, with most patients likely to die
within a year of diagnosis.
 Other Thyroid cancers
o Hurthle cell carcinoma: A form of follicular carcinoma that can metastasise to
the lymph nodes.
o Thyroid lymphoma: Almost always non-Hodgkin lymphoma and often have
concurrent thyroiditis, usually Hashimoto's.

10. 7
Epidemiology
 All types of thyroid cancer are 3 to 4 times more likely in women than men
 The risk of malignancy increases with age
 70% of thyroid cancers are papillary in nature
 Approximately 5% are medullary carcinomas
 Anaplastic carcinomas represent 2% of all thyroid
Aetiology & Risk Factors
The aetiology of thyroid cancer is not very well understood but contributing factors can put
an individual at higher risk of developing the disease.
Ionising radiation exposure is a major risk factor as radiation-induced cancers have a latency
period of 5-40 years with a peak at 15 years post exposure. Radiation induced papillary
cancer has been linked to patients who have undergone childhood irradiation for thymic
hyperplasia, ringworm and cervical lymphadenitis (standard treatment before antibiotics
were available).
Additionally, head and neck X-rays were standard medical practice until the 1960s as the
long term effects were unknown. Atomic bomb and other radiological disaster survivors
(Chernobyl) have shown an increased incidence in papillary carcinoma.
Iodine excess and deficiency has also been linked with an increased incidence in thyroid
cancer. In endemic goitre areas, where there is a dietary deficiency of iodine, follicular
cancer is more common. Conversely, papillary cancer is seen in areas where there is an
excess of iodine in the diet.
Other predisposing factors include:
 Genetic factors – linked with medullary thyroid cancer
 Females – 2-3 times more likely to get thyroid cancer than men
 Multiple Endocrine Neoplasia (MEN) Syndromes.
CHECKPOINT 2
1. What is the most common type of thyroid cancer?
2. Which is the only known type of thyroid cancer with a genetic link?
3. Are thyroid cancers more common in men or women?
4. List the risk factors that predispose an individual to thyroid cancer.
5. What is the incidence rate of anaplastic thyroid cancer?

11. 8
Clinical Features
A patient with thyroid cancer most commonly presents with a painless solitary lump in the
neck which can either arise from the thyroid itself or from surrounding cervical
lymphadenopathy (figure 6 & 7). The red flag symptoms suggesting thyroid cancer are
highlighted in figure 8.
Some patients complain of extracapsular symptoms including:
 Hoarseness – due to compression of one or both of the recurrent laryngeal nerves
innervating the vocal cords
 Dysphagia – if the tumour is large it can cause extrinsic compression of the pharynx
or upper oesophagus. If the neck mass is small it could suggest retrosternal
extension.
 Diarrhoea & Flushing – this is almost exclusively seen in medullary cancer and is
thought to be due to the release of prostaglandins by the tumour.
It is crucial to elicit whether a history of exposure to ionising radiation or family history of
thyroid cancer exists.
Thyroid lumps have quite distinct characteristics:
 Usually unilateral
 Moves with swallowing
 Non-tender
 Firm/hard in consistency
 Well circumscribed
Right lobe papillary carcinoma of
the thyroid with lymphatic spread.
Large anaplastic thyroid cancer
with retrosternal invasion.
Figure 6 Figure 7

12. 9
The exact presentation of thyroid cancer can vary between the types of tumour:
 Papillary – very slow growth and often spreads to the lymph nodes.
 Follicular – Usually middle aged women and often spreads to bone and lungs.
 Medullary – cervical lymph nodes usually affected; intractable diarrhoea and flushing.
 Anaplastic – firm, rapidly growing thyroid mass, stridor, vocal cord paralysis, weight
loss and dysphagia.
Investigations
Thyroid function tests should always be taken to rule out hyper or hypothyroid conditions.
Any mass with euthyroid biochemistry should be suspected as cancer.
Fine Needle Aspiration (FNA) is the most cost-effective, pre-operative diagnostic tool
available to distinguish between benign and malignant masses (figure 9). It is normally
performed under ultrasound guidance for maximum efficacy (figure 10). Results are usually
expressed using the THY cytology grading system (figure 11). FNA can also be used to
sample lymph nodes to distinguish nodal enlargement from metastatic infiltration.
THY1 Non diagnostic
cytology
THY 2
(benign)
Non neoplastic
features
(goitre/thyroiditis)
THY 3
(suspicious)
All follicular lesions
thyroid
adenoma/carcinoma
THY 4
(suspicious)
Suspicious of
malignancy (1/3 are
malignant)
THY 5
(suspicious)
Diagnostic for
malignancy
Red Flag Features of Thyroid Cancer
1. Family history of thyroid cancer
2. History of previous irradiation or exposure to high environmental radiation
3. Child with a thyroid nodule
4. Unexplained hoarseness or stridor associated with goitre
5. Painless thyroid mass enlarging rapidly over a period of a few weeks
6. Palpable cervical lymphadenopathy
7. Insidious or persistent pain lasting several weeks.
Figure 11Figure 9 Figure 10
Figure 8

13. 10
Other tests used in the diagnosis of thyroid cancer are:
 Ultrasound scanning can determine whether the mass is cystic (benign) or solid
(malignant).
 In cases of suspected medullary cancer, calcitonin levels should be measured.
 Chest X-ray should be performed in all patients to exclude obvious pulmonary
metastases. These are usually small and numerous and can be described as a
‘snow-storm’ appearance (figure 12).
 CT scans of the neck are used to determine the tumour limits particularly in
retrosternal disease or for radiotherapy planning at a later date (figure 13). It must be
a non-contrast scan as contrast contains iodine and prevents the use of I131
for
approximately six months.
 Excisional biopsies are not routinely indicated unless an FNA was inconclusive,
suspicious or lymphoma is suspected. If the mass is USS positive, surgical resection
is immediately indicated.
 Isotope thyroid scanning can distinguish between functioning toxic nodules and
thyroid metastases from follicular or papillary carcinoma using the tracer iodine-123
(123
I). Normal iodine uptake is seen as ‘warm’ nodules, ‘hot’ nodules take up
excessive amounts of iodine and conversely ‘cold’ nodules do not take up any iodine,
usually a sign of malignancy. This is not used as a primary test due to its poor
sensitivity and specificity.
Chest X-ray showing pulmonary
metastases.
CT scans showing a papillary carcinoma. The
white arrow indicates the site of the primary
lesion.
Figure 12 Figure 13

14. 11
Staging
A staging system is a standardised way to summarise how large a cancer is and how far it
has spread. The TNM staging system is the most commonly used criteria. The T stands for
Tumour and describes the size of the tumour and its spread into surrounding tissues. N
represents Nodes, describing whether the cancer has spread to the lymph nodes close to
the site of the primary. Finally M represents Metastasis, describing the spread of cancer to
distant parts of the body.
Tumour
 TX - Primary tumour cannot be assessed.
 T0 – No evidence of a tumour.
 T1 – Tumour 1cm or less at greatest dimension. Limited to thyroid.
 T2 – Tumour >1cm but not >4cm at greatest dimension. Limited to thyroid.
 T3 – Tumour >4cm at greatest dimension. Limited to thyroid.
 T4 – Tumour of any size extending beyond thyroid capsule.
All classifications in this section can be subdivided into ‘a’ (solitary) and ‘b’ (multiple).
Nodes
 NX – Lymph nodes cannot be assessed.
 N0 – no nodal involvement.
 N1 – Regional lymph nodes involved:
o N1a – Ipsilateral cervical nodes.
o N1b – Bilateral, midline or contralateral cervical nodes or mediastinal nodes.
Metastasis
 M0 – No distant metastasis.
 M1 – Distant metastasis is present, involving distant lymph nodes, internal organs,
bones etc.
Once the values for T, M, and N are determined, they are combined to find the stage. The
stage is represented by a number and subcategorised by letters. Thyroid cancers, unlike
most cancers, are grouped into stages by considering both the subtype of cancer and the
patients’ age.
CHECKPOINT 3
1. What is the common presenting feature of thyroid cancer?
2. List the distinguishing characteristics of thyroid lumps.
3. What are the red flag features of thyroid cancer
4. What investigations should be performed when suspecting thyroid cancer?
5. What system is used to stage thyroid cancer?

15. 12
Management
Patients who present with red flag features (see figure 8, page 10) should be referred
urgently to an ENT or head and neck specialist and seen under the 2 week wait system. Any
patient with a thyroid lump and associated stridor should be referred for a same day review,
as the symptoms are suggestive of airway compression or recurrent laryngeal nerve
involvement.
Following the referral, all patients are discussed at a multi-disciplinary team meeting so an
appropriate management plan can be devised. The management of thyroid cancer can be
categorised into surgical, radiological and pharmacological interventions, however each type
of thyroid cancer has a slightly different treatment approach. Patients with medullary
carcinoma require a referral to endocrinology for screening for phaeochromocytomas which
needs to be done pre-operatively and referral to genetic services for screening.
Surgical Intervention
Surgical intervention may involve either a unilateral lobectomy or total thyroidectomy (figure
14). Total ipsilateral lobectomies are indicated in low risk patients with small (<1cm)
unilateral and isolated potentially malignant masses with no extracapsular extension. Total
thyroidectomies are indicated in high risk patients with a history of neck irradiation, bilateral
tumours, metastases or tumour extension beyond the thyroid capsule. If lymph nodes are
involved then a complete lymphadenectomy should be performed in addition to thyroid
surgery. In medullary and anaplastic carcinomas a total thyroidectomy should be performed
as first line treatment due to the high risk of metastases.
The aim of surgery is to provide samples to confirm diagnosis, examine the spread of tumour
and attempt complete resection if possible. In advanced disease tumour debulking can
achieve significant symptomatic relief (e.g. airway compression).
Preservation of the parathyroid glands is important and if they are unable to be preserved
during surgery, they can be auto-transplanted into an appropriate muscle or placed in
cryopreserve for transplant at a later date to preserve serum calcium homeostasis in the
body.
In medullary cancer prophylactic thyroidectomies are performed in disease free carriers of
the RET mutation (usually found between 1-3 years of age). If the patient is 7 years or older,
in the presence of abnormal ultrasound scans and elevated serum calcitonin, a total
thyroidectomy and cervical lymphadenectomy is performed regardless of tumour size.
Figure 14

16. 13
Radiological Intervention
The radiological interventions involved in thyroid cancer management involve radioiodine
scanning and radioiodine ablation. Both these procedures usually follow surgical
resection/debulking. Since radioiodine scanning and ablation relies on the uptake of
radioiodine it is only useful in papillary and follicular thyroid carcinomas. Medullary and
anaplastic cancers are poorly differentiated, meaning they do not exhibit thyroid cell
characteristics and therefore will not absorb radioiodine.
 Radioiodine scanning
Radioiodine (123
I) will be taken up by any active thyroid tissue and will appear as a
hotspot on a scan. The intensity of uptake can determine the location of any
malignant thyroid tissue. Thyroxine replacement therapy (see below) should be
stopped 2 weeks prior to scanning and a low iodine diet is recommended to elevate
the TSH.
 Radioiodine ablation
Radioiodine ablation can destroy any remaining glandular thyroid tissue and it should
begin 3-4 weeks after surgery, especially when the tumour is larger than 1cm. The
remnant thyroid tissue is rendered ‘iodine hungry’ by the patient observing a low
iodine diet and withdrawing thyroxine replacement. This increases the rate of
radioiodine uptake by increasing the level of TSH, leading to improved efficacy of the
treatment. The isotope used in ablation therapy is iodine-131 (131
I). Thyroxine should
be restarted 48 hours after ablation and a post-ablation scan performed 3-5 days
after to confirm the results of the treatment. Adverse effects include: neck discomfort,
nausea, radiation pulmonary fibrosis, cystitis and gastritis which are controlled
pharmacologically.
 External Beam Radiotherapy
External beam radiotherapy (EBR) therapy involves delivering directed high energy
x-rays to a tumour externally. It is carefully planned to minimise radiotherapy dose to
the surrounding normal tissues. EBR is used if surgery has been unsuccessful in
resecting or debulking the tumour sufficiently (figure 15).
Whole body Radioiodine scanning
The black spots highlight areas of
metastases throughout the body.
Figure 15

17. 14
Pharmacological Intervention
Pharmacological intervention can be further subcategorised into chemotherapeutics and
TSH suppression therapies.
 TSH Suppression Therapy
TSH can stimulate the growth of remnant thyroid tissue in well differentiated
carcinomas (papillary and follicular) therefore TSH suppression is necessary to avoid
proliferation of residual thyroid tissue post-surgery or radio-ablation.
Patients take either T3 or T4 supplements which stimulate negative feedback to the
hypothalamus and pituitary, stopping TSH secretion (see page 5).
T3 is the replacement drug of choice prior to a scan as it has a shorter half-life
meaning it can be stopped for a shorter time before a radioiodine scan. T4, however,
is the preferred long term treatment. TSH levels should be monitored regularly to
ensure that it remains undetectable (<0.1mU/L).
 Chemotherapeutics
Chemotherapy is only considered when prognosis is poor. The agents of choice are
doxorubicin and/or cisplatin. This can cause the tumour to reduce in size.
Chemotherapeutics are used predominantly in anaplastic and refractory medullary
carcinomas, however response rates are only 20%. New chemotherapy agents have
shown promise and are currently in phase 3 trials e.g. Sorafenib.
Complications
 Surgical
Specific complications include the risk of secondary haemorrhage during the post-
operative period, laryngeal oedema, hypoparathyroidism (which can lead to
hypocalcaemia) and vocal cord palsy from damage to the recurrent laryngeal nerves
causing dysphonia and possible respiratory obstruction if there is a bilateral palsy.
 Radiotherapy
EBR to the neck will cause acute radiation laryngitis characterised by sore throat,
dysphagia and dysphonia. Late complications include subcutaneous fibrosis leading
to reduced neck movements.
 Radioiodine
Severe adverse reactions to radioiodine are rare. Possible complications include
nausea, acute parotitis, acute pneumonitis (if lung metastases) and induction of
cancer elsewhere. Acute thyroiditis can cause upper airway obstruction in severe
cases. These side effects of treatment can be treated effectively with corticosteroids.

18. 15
 TSH suppression therapy
Complications from this therapy are usually associated with inappropriate dosage or
poor patient compliance. This can lead to either hyper or hypothyroidism.
Hypothyroidism is serious in papillary and follicular carcinomas as it leads to a
physiological rise in TSH which can have an adverse effect on occult residual
disease in that it promotes tumour growth.
Follow Up
All patients with thyroid cancer should be followed up 3 monthly increasing to 6 monthly then
annually thereafter.
Lifelong follow up is necessary to monitor response to treatment, late adverse effects of
therapies and detection of late recurrent disease.
Patients with follicular or papillary carcinoma should have their thyroglobulin levels checked
(whilst on TSH suppression therapy) to detect recurrent or persistent disease. Thyroglobulin
is used by the thyroid gland to produce T3 and T4, therefore following a total thyroidectomy
and ablation therapy thyroglobulin levels should be undetectable. It is a reliable marker to
detect any residual thyroid tissue or metastases. Additionally TSH levels should be checked
to ensure adequate suppression; they should be very low or undetectable. Measurement of
thyroglobulin levels can only be done in patients with a total thyroidectomy.
The outcome of treatment should be checked between 6-8 months by radioiodine scan and
remission can be declared only after two successive negative scans.
Medullary carcinoma should be monitored with regular serum calcitonin blood tests to
assess disease. Increasing levels should warrant further investigations and treatment.
Octreotide is an octapeptide which mimics natural somatostatin and can be used to treat
refractory flushing and diarrhoea in medullary carcinoma.
Patients with anaplastic carcinoma have such a poor outlook; their follow up tends to be with
the oncologist and palliative care team.
Annual reviews should include:
 Careful patient history and clinical examination – especially neck palpation.
 Medical imaging – chest x-ray, ultrasound, CT and MRI scans if necessary.
 Serum calcium levels.
 Assessment of TSH suppression
 Serum thyroglobulin levels.

19. 16
Prognosis
Well differentiated tumours carry a better prognosis with survival higher in young people
without spread.
 Papillary – 20 year survival is >90% if the carcinoma is small and intracapsular. The
prognosis is slightly worse in the elderly where the disease tends to be more
aggressive with lung metastases in the form of lymphangitis carcinomatosis
(inflammation of lymph vessels secondary to malignancy).
 Follicular – 20 year survival is 60-70%. Invasion into blood vessels is associated with
a higher mortality rate.
 Medullary – 20 year survival is 70-80%. Less differentiated variants are associated
with poorer survival.
 Anaplastic – Most patients die within a year.
Differential Diagnosis of Lumps in the Neck
Patients may feel embarrassed when they see you regarding their presenting complaint. It is
important that you allow them to tell their story and maintain their dignity during your
examination. During the consultation you should aim to take an accurate history and
consider the differentials for their complaint(s).
Benign conditions are common but it is important to consider more sinister causes of neck
lumps so as not to miss the diagnosis in primary or secondary care. Knowing the underlying
anatomy and physiology can assist you in understanding the pathology that can develop.
The cornerstones of forming a solid differential diagnosis are taking a good history and
examination including: family history, age, lifestyle and risk factors.
CHECKPOINT 4
1. What surgical interventions can be performed for patients with thyroid cancer?
2. What glands are preserved (as much as possible) during thyroid surgery?
3. What is radioiodine ablation?
4. What is the importance of TSH suppression therapy?
5. What is the role of Octreotide in the management of thyroid cancer?

20. 17
Superficial and Submandibular Region
Condition Characteristics
Sebaceous cyst Common epidermal cysts.
Clinically tethered to the epidermis.
Lipomata Commonest benign tumour
Usually found in subcutaneous layer
Carbuncles Confluent infection of multiple hair follicles.
Limited to subcutaneous layer.
Neurofibromata Slow growing benign tumours.
Usually posterior nerve roots of spinal cord.
Lymph Nodes Infectious (TB, HIV, Glandular fever, URTI).
Malignancy (lymphoma, thyroid carcinoma, metastases).
Anterior Triangle of the Neck
Condition Characteristics
Thyroglossal cyst Painless, fluid filled cysts,
Commonly seen in people under 20 years old
Moves on tongue protrusion and swallowing
Dermoid cyst Epithelium lined cyst which may contain other skin products (hair
etc.). Commonly appears during first year of life.
Thyroid swelling Moves on swallowing but not tongue protrusion.
Examples: Goitre, Carcinoma.
Carotid aneurysm Rare, usually post-traumatic, atherosclerotic or post-
endarterectomy.
Presents as pulsatile lateral neck swelling & carotid territory TIAs.
Carotid body tumour Slow growing tumour, arising from carotid body at the carotid
bifurcation.
Slowly enlarging mass which transmits pulse.
Mobile from side to side but not up and down.
Sternomastoid
tumour
In babies following birth trauma; the head is turned away from
swelling and is tilted toward the lesion.
Laryngocoele Painless anterior triangle lumps made worse by blowing.
Branchial cyst Most common in young adults. Smooth swelling on anterior border
of the sternocleidomastoid at the junction of the upper and middle
thirds. The position is characteristic.
Fluctuant and can increase in size during respiration and infection.

21. 18
Posterior Triangle of the Neck
Condition Characteristics
Cystic Hygroma Congenital lesion comprised of lymph-filled spaces.
Presents as soft, fluctuant and highly transilluminable lump just
beneath skin.
Cervical Rib Overdevelopment of the costal element of the 7th
cervical vertebra.
CHECKPOINT 5
1. List as many differentials for neck lumps as possible?
2. What are the clinical features of a thyroglossal cyst?
3. A patient presents with a pulsatile lateral neck swelling. What is the likely
diagnosis?
4. Where do branchial cysts typically present?
5. What is a cystic hygroma?

22. 19
CHECKPOINT ANSWERS
I am not going to provide the answers on this page. Instead I am inserting the page where you
can find the answers to the questions. This, hopefully, will be more beneficial to your learning.
CHECKPOINT 1
1. Page 3 – Anatomy of the Thyroid Gland
2. Page 3 – Anatomy of the Thyroid Gland
3. Page 5 – Function of the Thyroid Gland
4. Page 3 – Anatomy of the Thyroid Gland
5. Page 4 – Anatomy of the Thyroid Gland
CHECKPOINT 2
1. Page 7 – Thyroid Cancer
2. Page 7 – Thyroid Cancer
3. Page 8 – Epidemiology
4. Page 8 – Aetiology & Risk Factors
5. Page 7 – Thyroid Cancer
CHECKPOINT 3
1. Page 9 – Clinical Features
2. Page 9 – Clinical Features
3. Page 10 – Clinical Features
4. Page 10/11 – Investigations
5. Page 12 - Staging
CHECKPOINT 4
1. Page 13 – Management – Surgical Intervention
2. Page 13 – Management – Surgical Intervention
3. Page 14 – Management – Radiological Intervention
4. Page 15 – Management – Pharmacological Intervention
5. Page 15 – Complications
CHECKPOINT 5
1. Page 17/18 – Differential Diagnosis of Lumps in the Neck
2. Page 18 – Differential Diagnosis of Lumps in the Neck – Anterior Triangle of the Neck
3. Page 18 – Differential Diagnosis of Lumps in the Neck – Anterior Triangle of the Neck
4. Page 18 – Differential Diagnosis of Lumps in the Neck – Anterior Triangle of the Neck
5. Page 19 – Differential Diagnosis of Lumps in the Neck – Posterior Triangle of the Neck

23. 20
Summary Table of Thyroid Cancer
Type Papillary
Carcinoma
Follicular
Carcinoma
Medullary Carcinoma Anaplastic
Carcinoma
Proportion of
Thyroid
Cancer
70% 10% 5% 2%
Age of
Incidence
35 – 40 years 30 – 60 years Isolated: 40-50 yrs.
Genetic: 10-20 yrs.
Over 60 years
Cell
Differentiation
Well differentiated Well Differentiated Intermediately
Differentiated
Poorly
Differentiated
Primary Mode
of Spread
Lymphatic Haematogenous Lymphatic Lymphatic
Symptoms
Usually none.
May experience:
- Hoarseness
- Swollen lymph
nodes
Same as papillary
cancer except
swollen lymph
nodes are rare
Usually none
Diarrhoea and
flushing are classic
Hereditary signs:
- Hypertension
- Tachycardia
- Headaches
Difficulty breathing,
hoarseness &
swollen lymph
nodes
Diagnosis FNA – very
accurate.
FNA (not always
accurate.
Coarse needle
biopsy to confirm.
Family history or
previous MEN
diagnosis.
FNA – usually
accurate.
Calcitonin blood test.
Coarse needle
biopsy.
Surgical biopsy
(very accurate)
Treatment Surgery &
radioablation &
TSH suppression
Surgery &
radioablation & TSH
suppression
Surgery
+
/- EBR
Early: surgery
Late: Palliative
care
Prognosis
90%+ at 20 years 60-70% at 20 years 70-80% at 20 years.
(variable depending
on differentiation)
<5% at 20 years
Most die within a
year.

24. 21
Further Resources / References
 Moore KL & Dalley AF. The Neck. In: Clinically Oriented Anatomy. 5th
ed. USA:
Lippincott Williams & Wilkins, 2006:1081-2.
 Tortora GJ & Derrickson B. The Endocrine System. In: Principals of Anatomy and
Physiology. 11th
ed. USA: John Wiley & Sons, Inc, 2006:634-638.
 GP Notebook, http://www.gpnotebook.com/simplepage.cfm?ID=-1006239721
 NHS Direct, http://www.nhs.uk/Conditions/Cancer-of-th-thyroid/Pages/Introduction
 Patient.co.uk, http://www.patient.co.uk/doctor/Thyroid-Carcinoma.htm
 Map of Medicine, http://app.mapofmedicine.com/mom/106/page.html?department-
id=3&specialty-id=1007&pathway-id=3054&page-id=7185&history=clear
 Tobias J & Hochhauser D. Thyroid and Adrenal Cancer. In: Cancer and its
Management. 6th
ed. UK: John Wiley & Sons Ltd. 2005:374-82.
 Neal AJ & Hoskin PJ. Endocrine Tumours, Thyroid Cancer. In: Clinical Oncology:
Basic Principals and Practice. 4th
ed. UK: Hodder Education. 2009:239-45.
 Netter FH. Head and Neck, Thyroid Gland. In: Atlas of Human Anatomy. 2nd
ed. USA:
ICON Learning Systems. 2001:68-70.
Should you have any questions or would like any further information on this
resource please do not hesitate to contact me.
Best wishes for your studies and beyond.
Adam Beebeejaun (Fourth Year Medical Student, Plymouth)
Doctors as Teachers SSU
adam.beebeejaun@students.pms.ac.uk