Thyroid 2 (633-647)

Question 1

What does Thy3 in FNAC mean?;

Answer 1

Thy 3 is an indeterminate lesion (possivle malignancy), either atypia or a follicular neoplasm

Question 2

What would be the next most appropriate management plan for this patient?;

Answer 2

Requires diagnostic hemithyroidectomy for histology to determine if malignancy.

Question 3

What are the stages in the ‘Thy’ calssification?;

Answer 3

FNAC scores. Thy1- inconclusive and requires further sample. Thy2- benign lesion. Thy3- indeterminate lesion (possible malignancy). Thy4- suspicious of malignancy (likely needs diagnositic hemithyroidectomy). Thy5- malignant (treatment depends on subtype_

Question 4

What are the common types of thyroid cancers?;

Answer 4

Papillary carinoma (most common - 75%), Folucular carcinoma (15%), Medullary carcinoma, Anaplastic thyroid cancer, Lymphoma

Question 5

What is the age of presentation of the different types of thyroid cancers?;

Answer 5

Papillary carinoma (40-50 year old in women), Folucular carcinoma (40 to 60 years old in women), Medullary carcinoma (40-50 years old), Anaplastic thyroid cancer (older woman around age of 65), Lymphoma (eldery over 60)

Question 6

What is the mode of spread of the different types of thyroid cancers?;

Answer 6

Papillary carinoma (spread via lymphatics), Folucular carcinoma (via haematogenous spread to bones and lungs), Medullary carcinoma (both lymphatic and blood - poor. prognosis), Anaplastic thyroid cancer (very aggressive with early local invasion and regional spreak (lymph and blood)), Lymphoma (grow radpidly)

Question 7

What are the key characteristic features of papillary carcinomas of the thyroid?;

Answer 7

Multiple lesions within the gland. Histologically are a mixture of papillary and colloid filled follicles with papillary projections and pale empty nuclei.

Question 8

What are the key characterisitic features of follicular carcinomas of the thyroid?;

Answer 8

Focal encapsulated lesions (multifocal disease rare). Microscopic capsular invesion (hurthle cell tumours).

Question 9

How are papillary and follicular carcinomas treated?;

Answer 9

Papillary- <4cm hemithyroidectomy. >4cm total thyroidectomy. Remove lymph nodes if involved. Follicular- Total thyroidectomy. No role for lymph node removal (spread haemtogenously). Radio-iodine can be used to kill any residual cells for both (contraindicated in pregnancy or children).

Question 10

What are the key features medullary carcinoma of they thyroid?;

Answer 10

Arise from parafollicular cells (C cells derived from the neural creast cells). Produce raised calcitonin levels and associated with MEN 2a and 2b syndromes. Poor prognosis as both lymphatic and haemtogenous spread.

Question 11

What other conditions ay be associated with medullary carcinoma of the thryoid?; ADD PIC MEN SYNDROMES

Answer 11

MEN 2a and 2b

Question 12

How are medullary carcinomas of the thyroid treated?;

Answer 12

Total thyroidectomy and lymph node dissection. Assess for other MEN tumours - PET scan for neuroendocrine tumours.

Question 13

What genes are associated with thyroid cancers?;

Answer 13

Papillary- BRAF, APC, RAS. Follicular- RAS. Medullary- RET gene.

Question 14

What is the most common type of thryoid lymphoma?;

Answer 14

B cell non-hodkgins. Associated with previous history of hashimotos.

Question 15

What tumour markers are used to monitor the prognosis of thyroid cancers?:

Answer 15

Papillary and follicular- thyroglobulin. Medullary- calcintonin.