Thyroid Cancer

Question 1

What is the most common histologic type of thyroid carcinoma?
A) Anaplastic
B) Medullary
C) Follicular
D) Papillary

Answer 1

D) Papillary

Papillary cancer accounts for about 85% of thyroid carcinomas.

Question 2

Risk Factor for Thyroid Cancer

Answer 2

Previous head and neck irradiation, particularly in early childhood

Question 3

Pathology of Anaplastic Carcinoma

Answer 3

Undifferentiated tumour of the thyroid follicular epithelium

Question 4

Pathology of Medullary

Answer 4

Unencapsulated neuroendocrine tumour arising from the parafollicular C-cells (the cell of origin of calcitonin).

Question 5

Inherited disorders associated with Medullary Carcinoma of the Thyroid

Answer 5

MEN type 2a and 2b (AD)

Question 6

For those who have MEN what is offered?

Answer 6

Thyroidectomy

Question 7

How to Screen with serum calcitonin

Answer 7

Problematic
Supranormal serum calcitonin response to IV calcium suggests C-cell hyperplasia or overt medullary carcinoma, but can get false positives, e.g. in autoimmune thyroid disease.

Question 8

Presentation of Papillary

Answer 8

Painless lump in the neck

Usually Clinically Euthyroid

Question 9

Presentation of Anaplastic

Answer 9

Rapidly enlarging neck mass that may be painful.
Confluent bilateral lymphadenopathy.
90% have regional or distant spread at diagnosis.
The commonest sites of metastases are lungs and bones.
± SVCO and/or Horner’s syndrome

Question 10

Presentation of Medullary

Answer 10

Unilateral Painless lump in the neck

Large tumours may have an associated paraneoplastic syndrome, e.g. Cushing’s syndrome due to corticotrophin secretion.

Question 11

Investigations

Answer 11

U: N/A
B: FBC, LFTs, Renal Function (for radioiodine therapy), Calcitonin
E:
I: CT of neck/mediastinum, MRI of neck, CT chest/liver, skeletal scintigraphy (lytic lesions)
S: High-resolution thyroid ultrasonography

Question 12

Prognosis for anaplastic cancer

Answer 12

Poor prognosis (like Stage IV)

Question 13

Papillary Carcinoma Staging

Answer 13

TMN stagin

Question 14

Medullary Carcinoma Staging

Answer 14

Stage I: 1° tumour <1cm, with no evidence of disease outside the
thyroid gland
Stage 2: 1° tumour >1cm or the presence of extrathyroidal
invasion, without nodal or distant metastases
Stage 3: Local or regional nodal metastases
Stage 4: Distant Metastases

Question 15

Management of Papillary Carcinoma

Answer 15

Surgery- total thyroidectomy

Question 16

Management of Medullary Carcinoma

Answer 16

Preoperative screening for phaeochromocytoma (MEN type 2) and
hyperparathyroidism with ↑ Ca (MEN type 2a)
Total thyroidectomy + central and ipsilateral neck node dissection