Thyroid Cancer

Question 1

Papillary thyroid cancer

Answer 1

MC
Women 3rd-5th decade

Papillary shaped cell groups w/o usual thyroid follicles or colloid

Ground glass cytoplasm
Large nuclei w/ nuclear grooves or inclusions that look like holes
“Orphan Annie eye nucleus” – nucleus looks clear
Psammoma body

Risk factors: tobacco use, radiation exposure

RET, BRAF, NTRK1 mutations

RET: Activation of tyrosine kinase receptor

Good prognosis
Risk of recurrence

Tx:
Total thyroidectomy then radioactive iodine tx – larger dose
Helps prevent recurrence

Question 2

Follicular thyroid carcinoma

Answer 2

2nd MC

uniform cuboidal cells lining follicles surrounded by fibrous capsule

invasive

spread hematogenously

RAS mutation
PAX8-PPARgamma 1 rearrangment

Females

Tx: total thyroidectomy followed w/ radioactive iodine tx

Question 3

Follicular adenoma of thyroid

Answer 3

Proliferation of follicle w/ fibrous capsule
Don’t invade capsule
Can secrete tumor

Use gene expression test on FNA to distinguish from follicular thyroid carcinoma

Question 4

Medullary thyroid cancer

Answer 4

Proliferation of parafolicular C cells – secrete calcitonin

Assoc w/ MEN2A, 2B – must screen for pheochromocytoma before surgery

RET gene mutation -> activation of tyrosine kinase receptor
NTRK1

Tx: total thyroidectomy, no radioactive iodine

Question 5

Anaplastic thyroid cancer

Answer 5

Undifferentiated
MC in older pts
Rock hard thyroid w/ extension
Rapidly fatal

Question 6

Other cancers of thyroid

Answer 6

Metastatic disease

B cell lymphoma assoc w/ hashimoto dz

Question 7

Complications of thyroid surgery

Answer 7

Remove/damage parathyroid glands -> hypocalcemia

• perioral tingling, myalgia, cramping, tetany, seizures
• transient w/ stunned glands

damage to recurrent laryngeal N. -> hoarseness