Thyroid Nodules
Hyperthyroidism
Hyperparathyroidism
Thyroid cancer
Cancer continued
200
Describe the function of the two branches of the superior laryngeal nerve
- Superior laryngeal nerve:
- Arises from the vagus nerve as it exits the skull base
- Courses with the superior thyroid artery until 1 cm before the artery enters the superior pole capsule
- External branch → motor function
- It innervates the inferior constrictor and cricothyroid muscles.
- This nerve is the most commonly injured nerve in thyroidectomies.
- Injury leads to loss of voice projection and increased fatiguability of the voice.
- Internal branch → sensory to larynx
- Injury can increase the risk of aspiration.
200
What are the 3 hormones produced by the Thyroid gland
- Hormones made within the thyroid gland include thyroxine (T4), triiodothyronine (T3), and calcitonin.
200
Which branchial pouches the do superior and inferior parathyroid glands originate from
- The superior parathyroid glands are derived from the fourth branchial pouch. They are located posterolateral to the recurrent laryngeal nerve (RLN).
- The inferior parathyroid glands are derived from the third branchial pouch. They are located anteromedial to the RLN.
200
This is the most common thyroid cancer and spreads via what? (hematogenous vs lymph)
- Papillary thyroid cancer (PTC). This is the most common thyroid cancer composing 80% of cases. The prognosis is excellent when PTC is localized to the thyroid gland. PTC spreads via the lymph nodes.
- Follicular thyroid cancer (FTC). This constitutes 10% of all thyroid cancers and is more prevalent in the setting of iodine deficiency. Spread is hematogenous. FTC has a slightly worse prognosis than PTC.
200
Following total thyroidectomy for well differentiated thyroid cancer, this can be used as a tumor marker for surveillance?
In general when should this be initially checked post (timeframe)
Thyroglobulin
3-6 months post op
should also check a TSH
obtain U/S 6-12 mo postop
400
Describe 3 sonographic findings (of thyroid nodules) that are concerning for underlying malignancy
Solid hypochoic nodule or solid hypoechoic
component of a partially cystic nodule with one
or more of the following features:
1. irregular margins (infiltrative, microlobulated)
2.microcalcifications
3. taller than wide shape
4. rim calcifications with small extrusive soft tissue
component
5. evidence of extrathyroidal extension
400
What is the most common cause of Hyperthyroidism
Graves disease
400
What is the most common cause of Primary hyperparathyroidism
solitary adenoma (80-90%)
400
What are two buzzword histologic findings in Papillary thyroid cancer?
1.psammoma bodies (concentric lamellated calcified structures)
2. intranuclear inclusions and grooves, and papillae, with empty-appearing nuclei (“Orphan Annie eyes”)
400
For which thyroid cancers is RAI indicated?
This therapy is indicated for patients with PTC or FTC after total thyroidectomy who have the following:
- Large tumors (> 4.0 cm)
- Distant metastases
- Gross extrathyroidal extension or aggressive histologic features
- Tumors from 1 to 4 cm with high-risk histology, vascular invasion, or cervical lymph node metastases
600
The recurrent laryngeal nerve is (motor, sensory, or both)
injury to the RLN results in this?
- Responsible for sensory and motor function of larynx (all muscles except the cricothyroid)
- hoarseness
600
This is the most important factor regarding prognostication of well differentiated thyroid cancer
- Age is the most important factor regarding prognosis of well-differentiated thyroid cancer.
- If the patient is younger than age 55, the cancer can only be stage 1 or stage 2.
600
What are the 3 ways PTH helps to increase serum calcium
PTH increases serum calcium by:
- Increasing bone resorption
- Increasing renal calcium absorption in the ascending loop of Henle and distal convoluted tubule
- Increasing conversion of 25-OH vitamin D to the active 1,25(OH)2D, which increases intestinal absorption of calcium
600
How do you diagnose follicular thyroid cancer?
- FNA cannot be used to distinguish between benign and malignant follicular neoplasms because FTC is defined by capsular or vascular invasion (as compared with follicular adenomas, which are noninvasive).
- need diagnostic/therapeutic lobectomy
600
Patients with MTC should be screened for what gremlin genetic mutation?
- Genetic screening for germline RET mutation should be performed for all patients with MTC.
800
In general describe the management of a "hot" vs "cold" thyroid nodule
- In patients with suppressed TSH, thyroid scintigraphy distinguishes a solitary toxic nodule ("hot nodule") from a toxic multinodular goiter (heterogeneous uptake) or Graves hyperthyroidism (diffuse, increased uptake).
- Hot nodules (increased uptake on scan) are almost always benign and do not warrant fine-needle aspiration (FNA) biopsy.
- Cold nodules warrant further workup with a thyroid ultrasound and FNA biopsy.
800
Which is the preferred anti thyroid medication in pregnancy and why?
PTU is the preferred medication in pregnancy.
safe during first trimester as it does not cross the placenta
800
What are 4 indications for asymptomatic patients to undergo parathyroidectomy
- Age less than 50 years
- Laboratory studies: serum calcium greater than 1 mg/dL above the upper limit of normal
- Skeletal considerations
- Bony fracture
- Osteoporosis as measured with a bone density T-score less than or equal to –2.5 on DEXA at any site
- Renal considerations:
- GFR less than 60 mL/min
- Nephrolithiasis or nephrocalcinosis
- Hypercalciuria (> 250 mg/d for females and > 300 mg/d for males)
800
What is the surgical management of nonmetastatic medullary thyroid cancer?
What lab values are measured postoperatively as part of surveillance (two answers)
Nonmetastatic MTC should be treated with total thyroidectomy and bilateral central (level VI) neck dissection.
if nodes positive then MRND
CEA, calcitonin. Calcitonin more sensitive for recurrence
800
Patients presenting with serum calcium greater than 14mg/dl should raise concern for what pathology?
Parathyroid cancer
1000
DAILY DOUBLE
Describe the Bethesda criteria including all categories with the corresponding management
1000
Why is a Euthyroid state preferred prior to undergoing total thyroidectomy for hyperthyroidism? (to prevent what?)
what are the signs/symptoms and management of this condition
To prevent thyroid storm
signs - CV dysfunctions, CNS manifestiations, hypertherima
management - cooling blankets, RAI, thyroidectomy
1000
What would be the expected lab pattern of a patient with secondary hyperparathyroidism due to chronic renal insufficiency?
PTH, calcium, phosphate, vitamin D
elevated PTH levels,
hypocalcemia,
hyperphosphatemia,
hypovitaminosis D.
1000
How is thyroid lymphoma treated/managed?
- Thyroid lymphoma responds well to chemotherapy with rituximab, cyclophosphamide, doxorubicin (hydroxydoxorubicin), vincristine (Oncovin), prednisone (R-CHOP) and radiation.
1000
What is the surgical resection goal in parathyroid cancer?
- The mainstay modality for parathyroid carcinoma is complete surgical resection.
- The planned surgical technique for parathyroid carcinoma is en bloc resection of the tumor and any contiguous structures to which it may be adherent, including the ipsilateral thyroid lobe or the recurrent laryngeal nerve, which should be sacrificed if clinically involved.
- If preoperative findings indicate lymph node involvement, a therapeutic ipsilateral cervical compartment lymph node dissection is indicated.
- Intraoperative
- Intraoperative suspicion of carcinoma mandates complete en bloc resection of the tumor with grossly negative margins.