Tiemann Thyroid Nodules DSA

Question 1

Incidence of thyroid nodules and cancer

Answer 1

Palpable nodules found in about 5% of adults

Ultrasound studies (or autopsy studies) find nodules in ~50% of adults

Increasing incidence of thyroid nodules found on exams for other reasons

Only about 15% of nodules will be malignant

Incidence of thyroid cancer increasing, but mortality rate remains stable

The task is to identify those nodules that require surgery

Question 2

work-up of thyroid nodule: history

Answer 2

Identify higher or lower risk groups
Gender–nodules more common in women (x4), but more often malignant in men
Age–malignant nodules more common in ages<30 and >60
History of radiation exposure to head and neck
Family history of thyroid cancer, FAP, MEN, multiple hamartoma syndrome
Voice symptoms, visual symptoms, fatigue, anxiety (Sx of hypo or hyperthyroidism)

Question 3

workup of thyroid nodule: physical exam, labs, radiology

Answer 3

PHYSICAL EXAM
Character of nodule and thyroid
Solitary vs. multiple
Associated lymphadenopathy (anterior and posterior triangles)
Extrathyroidal manifiestations (voice, eyes, reflexes) looking for signs of hyper or hypo thyroidism

LAB
TSH, T4, T3

RADIOLOGY
Radionuclide scanning if hyperthyroid
Neck ultrasound

Question 4

FNA

Answer 4

Dependent on technique and pathologist
Best done under US guidance and small-bore needle
Requires pathologist trained in cytopathology
~90% sensitivity and specificity
Indicated for nodules >1cm and/or suspicious on US (hypoechoic, irregular, intranodular vascularity, calcifications, nodal metastases)
May need to aspirate multiple nodules, if more than one meets criteria (up to 4 nodules)

Question 5

FNA RESULTS

Answer 5

Inadequate specimen
- Requires repeat FNA

Benign
- Requires 6-12 month follow-up (5% false- negative rate)

Malignant
- Requires surgery

Indeterminant (follicular lesion)

• Usually contains follicular cells or Hurthle cells
• Formerly required surgery to examine entire nodule
• — Malignancy in follicular lesions determined by invasion of capsule or follicular cells in surrounding blood vessels or lymphatics
• Now can be further evaluated by gene-expression classifier profile with 90-95% sensitivity and specificity

Question 6

PAPILLARY CA ON FNA

Answer 6

Little Orphan Annie cells, intra-nuclear grooving, papillary projections, psammoma bodies

Question 7

SURGICAL TREATMENT OF PAPILLARY CARCINOMA

Answer 7

Total Thyroidectomy +/- Lymph node dissection
Survival rates depend on prognostic factors

Low-Risk vs. High-Risk
Age: <40 vs. >40
Sex: Female vs. male
Extent: Contained vs. capsular invasion, extrathyroidal extension
Metastasis: None vs. regional or distant
Size: <2cm vs. >4cm
Grade: Well-differentiated vs. poorly differentiated

Long-term survival varies from 50%-99%

Question 8

FNA = FOLLICULAR LESION

Answer 8

Stippled cytoplasm, sheets of cells

Question 9

FNA = HURTHLE CELLS

Answer 9

Extensive amyloid deposits in the cellular matrix

Question 10

FNA = INDETERMINATE

Answer 10

Follicular or Hurthle cell lesions
Formerly required the entire nodule for diagnosis to determine invasion of the capsule, lymphatics or blood vessels
Now evaluated first by gene-expression classifier method to determine liklihood of malignancy (NEJM, 2012)
If surgery indicated, lobectomy + isthmusectomy and frozen section
If malignant, then total thyroidectomy, no lymph node dissection
Occasionally FS benign and permanent sections malignant—decision on whether to do completion thyroidectomy dependent on degree of risk

Question 11

FNA = MEDULLARY CA

Answer 11

Large bi-lobed nuclei with intense staining, Parafollicular C-cells

Question 12

Medullary carcinoma

Answer 12

Parafollicular “C” cells which secrete calcitonin
5-10% of thyroid cancers, PTC and FTC ~90%
Sporadic (75%) Usually more indolent
Familial (25%)—MEN 2A (60%),2B (5%) or Familial (35%)
Screen for parathyroid and adrenal disease if 2B suspected
Pre-operative calcitonin levels
RET proto-oncogene in patient and relatives
Total thyroidectomy +/- lymph node dissection
Follow-up with serum calcitonin levels or stimulated calcitonin levels
RAI, serum thyroglobulin of no use in follow-up

Question 13

ANAPLASTIC THYROID CANCER

Answer 13

~ 1% of thyroid cancers

Very aggressive and often presents as a rapidly enlarging, painful mass with obstructive symptoms

Can be diagnosed with FNA

Palliative care only, doesn’t respond well to surgery, radiation therapy, or chemotherapy

Question 14

FOLLOW-UP OF THYROID CANCERS

Answer 14

Most well-differentiated epithelial thyroid cancer treated with post-op radioactive iodine to ablate subclinical disease or mets
Thyroid replacement
Monitor physical exam and thyroglobulin levels to look for recurrent disease
Medullary cancers followed with calcitonin and family evaluation
Use of PET scan promising, but not yet standard of care

Question 15

Surgery appropriate for:

Answer 15

Hot” nodule
Toxic nodular goiter
Grave’s Disease, especially in pregnant patient
Multinodular goiter

Surgery usually not performed in thyroiditis with hyperthyroidism

Thyroiditis usually self-limiting

Question 16

SURGERY FOR GOITER

Answer 16

Large goiters sometimes produce obstructive or pressure symptoms requiring resection

Occasionally a rapidly growing goiter may be worrisome for carcinoma and FNA or biopsy indeterminate

Question 17

COMPLICATIONS OF THYROID SURGERY

Answer 17

Recurrent laryngeal nerve injury
Superior laryngeal nerve injury
Hypoparathyroidism
Hypothyroidism
Extensive blood loss and infection rare