W5L6 - Thyroid FNA Part 2

Question 1

Clinical Features of Follicular Neoplasms

Answer 1

Difficult to distinguish benign from malignant
May cause hoarseness in the voice
Swallowing difficulties
May present as a goitre

Question 2

Follicular Adenoma

Answer 2

Defined as benign
Encapsulated
Most common thyroid neoplasm
Most patients present are ‘euthyroid’ and may have elevated thyroglobulin
More common in regions with iodine deficiency
Usually solitary lesions and characterised by a thin capsule that is microscopically complete
2° degenerative change such as haemorrhage, oedema, fibrosis cystic degeneration may occur

Question 3

Follicular Carcinoma - Clinical Features

Answer 3

Higher incidence in women than men
Often patient’s present with an asymptomatic thyroid mass or nodule that can be felt in the neck
Pain is seldom an early warning sign
Persistent cough
Difficulty breathing and swallowing
Palpable nodules are usually solitary with a hard consistency, an average size of less than 5cm and ill-defined borders.
Nodule is fixed in respect to surrounding tissues and moves with the trachea at swallowing

Question 4

Why is it difficult to distinguish between follicular adenoma and carcinoma on cytology?

Answer 4

Because a follicular carcinoma can also have a capsule and/or vascular invasion
Capsular/vascular invasion can’t be assessed on cytology making it difficult to diagnose between the two

Question 5

Follicular Neoplasm - Cytology

Answer 5

Syncytial sheets, repetitive pattern with uniform size microfollicles
Larger, crowded nuclei
Prominent, multiple nucleoli
Coarse irregular chromatin
Marked dispersion
Mitoses

Question 6

Hurthle Cell Neoplasm - Cytology

Answer 6

Cellular
Little to no colloid
Predominance of Hurthle cells forming microfollicles
Dispersion
Traversing blood vessels

Question 7

If you see ciliated cells in a thyroid smear, what are they?

Answer 7

Normally cells from the trachea

Question 8

Adequacy

Answer 8

5-6 fragments of epithelial cells each containing > 10 cells, on at least 2 slides
6-8 fragments of epithelial cells each containing 8-10 cells
Well preserved, well prepared smears

Question 9

High Risk Groups

Answer 9

Family history
Exposure to radiation (as child)
- Hiroshima/Nagasaki
- Chernobyl
- Fukushima
Medical irradiation

Question 10

DICER1 Mutations

Answer 10

Associated with autosomal dominant multi-nodular goitre (MNG)
Associated with Sertoli-Leydig cells tumours occurring with MNG
Other associations:
- pleuropulmonary blastoma
- cystic nephroma
- lung cysts

Question 11

Hereditary Thyroid Syndromes

Answer 11

DICER1 mutations in MNG +/- ovarian Sertoli-Leydig cell tumours
Familial medullary thyroid cancer (MTC)
Familial non-MTC
- non-syndromic non-MTC
- syndromic non-thyroidal tumours