Thyroid adenoma

Question 1

Describe the histology of a thyroid adenoma

Answer 1

Discrete, solitary masses
Encapsulated by a surrounding collagen cuff composed of neoplastic thyroid follicles (e.g. follicular adenoma)
Can secrete thyroid hormone

Question 2

How will thyroid adenomas present?

Answer 2

Discrete solitary neck mass
Often found incidentally
May cause thyrotoxicosis
May cause local symptoms such as dysphagia

Question 3

Who is most at risk of follicular adenoma?

Answer 3

Women
Increased age
Areas of iodine deficiency

Question 4

What are some genetic components of follicular adenoma?

Answer 4

• <20% have a mutant ras or PIK3CA
• Functional adenomas have an activating mutation in the TSHR signalling pathway → increased cAMP
• N-ras and K-ras mutations have been implicated in the evolution of follicular adenoma to follicular carcinoma

Question 5

How are follicular adenomas investigated?

Answer 5

USS
FNA (Cannot distinguish between adenoma and carcinoma)
Serum TSH

Question 6

How are follicular adenomas managed?

Answer 6

Lobectomy with biopsy is required for treatment and definitive diagnosis as FNA cannot distinguish between follicular adenoma and follicular carcinoma