Endocrine Flashcards
1
Q
What’s in the differential for adrenal nodule?
A
Hypercortisolism Hyperaldosteronism Catecholamine hypersecretion Androgen hypersecretion Benign, nonfunctional mass Adrenocortical carcinoma Mets
2
Q
What are the key 2 defining characteristics of an adrenal mass?
A
1 Hormone hypersecretion?
2 malignant?
3
Q
What are the findings on H&P of a patient that hyper secretes cortisol?
A
- Truncal obesity
- Moon facies
- Buffalo hump
- Proximal weakness
- Purple striae
- to name a few
4
Q
What’s the differential for hypercortisolism?
A
Exogenous
Adrenal
Pituitary: high ACTH
Lung: NSCLC
5
Q
What is the clinical presentation of an adrenal nodule that hyper secretes aldosterone?
A
Hypertension (refractory to severe agents) with hypokalemia
6
Q
What signs/symptoms are suspicious for adrenocortical carcinoma?
A
- Cushing’s
- Nonfunctional tumors: abdominal mass, pain, N, anorexia, early satiety, weight loss
- > 6cm
7
Q
What is the most common adrenal mass?
A
Nonfunctional benign adrenocortical adenoma (only 15% secrete hormones - cortisol being most common)
8
Q
Why does hyperaldosteronism cause hypertension and hypokalemia?
A
- Increase Na reabsorption to increase extra cell vol/BP
- K excreted to balance positively charged Na ions
9
Q
What is next step after adrenal adenoma is suspected or seen on imaging?
A
H&P with labs: test:
- cortisol
- catecholamines
- aldosterone if HTN
10
Q
What labs to draw for hypercortisolism?
A
- 24-hour urine free cortisol
- Low dose dexamethasone suppression test
- Serum/salivary cortisol at midnight * Plasma ACTH level if necessary
11
Q
What labs to draw to evaluate hyperaldosteronism?
A
- Serum aldosterone: renin ratio (>30 is diagnostic, 4-10 nl)
- Serum K+
12
Q
What labs to draw to evaluate for catecholamine hyper secretion / pheochromocytoma?
A
24-hour urine metanephrines and catecholamines OR
Plasma metanephrines/ catecholamines
13
Q
What is the best imaging modality to evaluate an adrenal nodule? Another option?
A
CT with contrast
MRI another option
14
Q
What imaging characteristics of an adrenal nodule can help differentiate benign from malignant?
A
Benign: < 4cm, homogenous, well-defined borders, low vascularity, rapid contrast washout
Malignant: >6cm, irregular borders with necrosis, calcification and/or hemorrhage in mass
15
Q
What is the treatment for a nonfunctional adrenal mass?
A
< 4cm: observe with interval CT scans
>6cm or concerning features: Resect
4-6cm: depends on other risks, resect if good surgical risk
16
Q
What is the surveillance protocol for an adrenal nodule that will not be resected?
A
- Repeat imaging: 6, 12, 18 months
- Repeat biochemical evaluation for hormone levels every 4 years
17
Q
What is the treatment for a functional adrenal mass?
A
Surgical resection
18
Q
What are important perioperative management principles for patients with Cushings?
A
Peri/post op GC replacement
19
Q
What are important perioperative management principles for patients with hyperaldosteronism?
A
Spironolactone and K pre-op
20
Q
What are important perioperative management principles for patients with pheo?
A
Alpha blockade 10-14 days prior to surgery: unopposed alpha stimulation can cause severe vasoconstriction and HTN
21
Q
What is the venous drainage of L vs. R adrenal?
A
L: left adrenal to left renal
R: right adrenal to IVC
22
Q
What is a critical portion of the right adrenalectomy?
A
Control right adrenal vein because it enters IVC!
23
Q
Why do we not biopsy adrenal masses?
A
Could be a pheo which may release massive amounts of catecholamines
24
Q
What is the prognosis of an adrenal adenoma:
A
Benign: excellent
Functionally secreting aldosterone: resolution of HTN in 70-90%
25
What is the differential for hypercalcemia?
```
Chimpanzees:
Calcium supplements
Hyperparathyroidism
Hyperthyroidism
Immobility
Iatrogenic (HCTZ)
Milk alkali syndrome
Paget's dz
Addison's dz
Acromegaly
Neoplasm
Zollinger-Ellison syndrome
Excessiev vitamin D
Excessive vitamin A
Sarcoidosis
```
26
What is most common cause of hypercalcemia in hospitalized patients?
Malignancy
27
What is most common cause of hypercalcemia in outpatients?
primary hyperparathyroidism
28
What causes humoral hypercalcemia of malignancy?
80% PTHrP
| 20% cytokines/chemokines
29
What causes familial hypocalciuric hypercalcemia?
CASR mutation: lack of Ca signal increases PTH level with increases renal Ca absorption. Less Ca in urine
30
How does hypercalcemia present?
Stones: kidney stones
Bones: aching bones
Groans: abdominal pain
Moans: neuropsychiatric
31
What are renal manifestations of hypercalcemia?
Nephrolithiasis
Nephrocalcinosis
Polyuria, polydipsia
Hypertension
32
What are GI manifestations of hypercalcemia?
constipation
N/V
Heartburn
Ab pain
33
What are neuro manifestations of hypercalcemia?
```
fatigue
depressed mood
difficulty concentrating
impaired memory
anxiety
sleep change
```
34
What patient demographic most commonly presents with hyperparathyroidism?
postmenopausal women
35
What are risk factors for primary hyperparathyroidism?
Ionizing radiation
Family history
Lithium for bipolar
36
What are d/o or MEN-1?
Hyperparathyroidism
Pituitary adenomas
Pancreatic neuroendocrine tumors
37
What are d/o or MEN-2A?
Hyperparathyroidism
Medullary thyroid cancer
Pheo
38
What are d/o or MEN-2B?
Marfanoid habitus
Oral neuromas
Medullary thyroid cancer
Pheo
39
What do we see for labs in primary hyperparathyroidism?
Elevatd Ca w/ high or inappropriately nl PTH
40
What do we see for labs in secondary hyperparathyroidism?
Decreased Ca
Increased intact PTH
In setting of renal dz
41
In asymptomatic patients with hypercalcemia, what do we do next?
Obtain DEXA for bone density
42
What are PTH's actions on bone and kidney?
Bone: increase breakdown for calcium absorption into blood
Kidney: Vitamin D activation
43
What's vitamin D's action in gut?
Increase Ca absorption
44
What is the indication for parathyroidectomy in asymptomatic patients with primary HPT?
```
1 Serum Ca > 1 more than UL nl
2 Cr clearance < 60
3 BMD w/ T score < 2.5 at any site
4 Age < 50
5 Patients that cannot undergo routine surveillance
```
45
What is the indication for parathyroidectomy in patients with secondary HPT?
```
High PTH level despite medical management
Bone pain
Pruritis
Progressive renal dz
Osteopenic fractures
Calciphylaxis
```
46
What do we do with a suspected PTH adenoma?
Localize it with sestamibi scan and ultrasound
47
What is the typical cause of primary HPT? What do 10-15% patients have?
Single parathyroid adenoma, but multiple gland parathyroid dz is present 10-15% patients
48
What is T-score? What does it represent?
Test of bone density, shows number of std deviations below average for a young adult at peak bone density.
- Normal > -1
- Osteopenia: -1 to -2.5
- Osteoporosis: < 2.5
49
Where can the inferior parathyroid glands hide?
mediastinum (thymus)
within carotid sheath
behind esophagus
50
How is primary HPT different in sporadic vs. MEN patients?
Sporadic: single adenoma
MEN: expressed in all glands = four gland hyperplasia
51
What is the pathophys of tertiary HPT?
Persistent excess PTH following renal transplant: very rare
52
What labs do we use to diagnose primary HPT?
Ca, phosphate, chloride, bicarb, mag, serum Cr, PTH level, 24 hour urine Ca
53
Does elevated PTH + elevated serum Ca diagnose primary HPT?
No: need urine Ca to rule out hypocalciuric hypercalcemia
54
What is total serum Ca vs. ionized Ca?
```
Total = protein-bound + free Ca
Ionized = free only
```
55
If serum Ca high, but PTH is normal, can we r/o primary HPT?
No: PTH should be low! This suggests primary HPT
56
How can serum Cl to phosphate ratio suggest primary HPT?
> 33: PTH acts on kidneys and increased Ca reabsorption and excretion of bicarb and phosphate. Excretion of bicarb = rise in serum Cl to balance ions = hyperchloremic metabolic acidosis
57
What XR findings are associated with bony involvement in HPT?
- Hands: subperiosteal cortical bone resportion in distal phalanges
- Rarely: osteitis fibrosa cystica
58
What tests help to localize the involved gland in HPT?
Sestamibi scanning and ultrasound
59
What tissues take up sestamibi? Why does it matter?
Parathyroid and thyroid - thyroid nodule can mimic appearance of parathyroid adenoma.
60
What is the non-op management of patients with HPT?
- monitor Ca and Cr annually
- Measure bone mineral density every 1-2
- Bisphosphonates or Cincalcet if needed
61
What is the role of intraoperative PTH monitoring?
- Draw PTH level at time of gland excisio and again 10 min post resection
- Fall of > 50% of PTH associated with 98% cure rate
62
What is post-op management after parathyroidectomy?
Monitor for:
- Neck hematoma
- Voice change (recurrent laryngeal nerve)
- Perioral numbness
- Tingling in finger
63
What is the treatment for neck hematoma with stridor?
Immediate bedside decompression + evacuate hematoma and hemostasis in OR
64
What are benefits of parathyroidectomy?
- Increases in bone mineral density at multiple sites
| - Decreased risk of new kidney stones
65
Why does post-op hypocalcemia occur after parathyroidectomy?
High levels of PTH lead bone to be chronically starved of Ca - bones will voraciously absorb Ca after surgery
66
If patient with hypocalcemia doesn't respond to Ca repletion, what to do?
Check mg: hypomagnesemia can cause refractory hypocalcemia due to inhibition of PTH bioactivity
67
How to treat hypercalcemic crisis?
1 Aggressive infusion of normal saline
2 Loop diuretics once euvolemic
3 Bisphosphonates
68
What are the symptoms of pheochromocytoma?
```
Episodic hyperadrenergic symptoms (5 P's):
Pressure (HTN)
Pain (HA)
Perspiration
Palpitation
Pallor
```
69
What disorders are pheochromocytomas associated with?
MEN 2
NF -1
VHL disease
70
What cells are pheos derived from?
Chromaffin cells in the adrenal medulla or sympathetic ganglia
71
What are the predominant catecholamines released by pheos?
NE > Epi
72
What are the triggers of hypertensive crisis in pheo?
```
Changes in blood flow
Physical stimulation
Tumor necrosis
Anesthetic agents
Foods containing tyramine
Surgical manipulation
```
73
How do we determine if a pheo is malignant?
Local invasion, NOT cellular features
74
How is pheo diagnosed?
24 hour Urine / blood levels of catecholamines and their metabolites: > 2x UL nl is diagnostic
- Plasma-free metanephrine is most sensitive: higher false positives
75
What is first line imaging for pheo?
CT or MRI with contrast
76
When do we use I-MIBG for pheo diagnosis?
Cases of suspected multifocal or extra-adrenal disease
77
What is the first step in management of a pheo?
Medical conditioning: alpha blockade for > 2 weeks
78
When are beta blockers used for pheo before surgery?
For tachycardia and/or arrhythmia
79
What is the definitive treatment for pheo?
Surgical resection
| - Laparoscopic if <8cm and have no malignant features on imaging
80
Why don't we biopsy adrenal masses?
Can trigger hypertensive crisis due to release of catecholamines
81
Why do we never give a beta blocker first for pheo treatment?
Unopposed alpha constriction: can cause hypertensive crisis
82
What is the classic triad of symptoms in pheo?
HA
Flushing
Palpitations
83
Besides the classic triad, what are other symptoms of pheo?
Sustained or episodic HTN
84
Why can pheo patients present with orthostatic hypotension?
Large amounts of catecholamines can desensitize adrenergic receptors
85
Can pheo be asymptomatic?
Yes: incidentaloma on CT scan
86
What percent of pheos are a result of underlying familial syndrome?
20-40%
87
How do dopamine secreting tumors present?
Watery diarrhea
88
Where do pheos develop?
Majority: adrenal medulla
| If extra-adrenal: paragangliomas
89
Why do patients with pheo have elevated hematocrit levels?
Chronic alpha constriction: volume depletion and hemoconcentration
90
Why do pheo patients have hyperglycemia?
Catecholamines stimulate hepatic glucose production and inhibit insulin secretion and action
91
What is the treatment for pheo?
1. Alpha blockade w/ occasional beta blockade for at least 2 weeks
2. Surgical resection
92
Who gets beta blockers before surgery for pheo?
Those who develop tachycardia after adequate alpha blockade
93
What are the main complications of adrenalectomy for pheo?
Hypertension
Hypotension
Hypoglycemia
Arrhythmia (from HTN crisis)
94
How often should plasma and urinary catecholamines be measured postoperatively for pheo?
- 2 weeks after surgery
- Every 3 months for year
- Annually afterwards
95
What is the overall prognosis for pheo?
- Surgical resection is usually curative
| - Malignant: palliative treatment
96
What are the risk factors for thyroid cancer?
Ionizing radiation
| Family history
97
What is the most important initial test for suspected thyroid disease?
TSH
98
How should thyroid nodules be evaluated with elevated TSH?
- Ultrasound
| - radioactive iodine scan
99
What is the prognosis for iodine avid, "hot" thyroid nodules?
Good: low risk of malignancy
100
Which thyroid nodules should undergo FNA?
- > 1cm
- Suspicious US findings
- Increasing in size
101
How are thyroid nodules evaluated?
US
102
What cells do papillary and follicular thyroid cancers arise from?
Follicular cells
103
What cells do medullary thyroid cancers arise from?
Parafollicular "C" cells
104
What is the most important part of the initial workup for a thyroid nodule?
FNA
105
If FNA is inadequate, what is the next step for thyroid nodule?
Repeat FNA
106
If FNA is benign, what is the next step of a thyroid nodule?
Observe
107
If FNA is suspicious for follicular neoplasm, what is the next step?
Diagnostic thyroid lobectomy
108
If FNA is suspicious for malignancy, what is the next step?
Consider total thyroidectomy
109
If FNA shows malignant cells, what is the next step?
Total thyroidectomy and consider neck dissection
110
In patients with medullary thyroid cancer, what is important to investigate?
Underlying germ line mutation (present in 25% patients)
111
Before surgery for medullary thyroid cancer, what must be ruled out and why?
Pheo due to risk of MEN syndromes
112
Where does ectopic thyroid tissue in the lateral neck metastasize?
Cervical lymph nodes
113
What does numbness and tingling in the lips and fingers after total thyroidectomy signify? How to treat?
Hypoparathyroidism: treat with oral Ca
114
Post-operative neck swelling after thyroidectomy with stridor, what is it? How to treat?
- Hematoma compressing the airway
| - Surgical emergency: bedside decompression
115
How common are thyroid nodules, and how often are they cancerous?
5% of population
| 95% of them are benign
116
What is the thyroid status of most thyroid carcinoma patients?
Euthyroid
117
What is the most common cause of death in patients with thyroid storm? Who gets this?
High output cardiac failure: post-op patients with undiagnosed Graves disease
118
How to treat high output cardiac failure from Graves dz in post-op patients?
Beta blockers
| PTU
119
What is the significance of the mass moving up and down with swallowing?
Thyroid gland moves up when a patient swallows due to attachment to trachea via ligament of Berry: likely to be a thyroid mass
120
How do we determine prognosis of papillary thyroid cancer?
Presence of local invasion
121
Why does metastatic medullary carcinoma frequently cause diarrhea and flushing?
High calcitonin levels
122
Why can't FNA be used to diagnose follicular thyroid cancer?
Histologic diagnosis: need to see if proliferation of follicles invades capsule
123
What is considered well-differentiated thyroid cancer?
Anything from follicular cells: Papillary, follicular and Hurthle cell carcinomas
124
Which cancers can produce psammoma bodies?
Papillary thyroid cancer
Serious cystadenocarcinoma of ovary
Meningioma
Mesothelioma
125
What labs are for thyroid mass?
TSH, do T4/T3 if abnormal
126
Do we use nuclear imaging for an isolated thyroid nodule?
Not usually: FNA standard now
127
What is the next step for a benign FNA result?
Annual follow up with US
128
What is the next step for an FNA that reports AUS or FLUS (atypia of undetermined significance or follicular lesion of undetermined significant)?
Repeat FNA
129
What is the advantage of total thyroidectomy in thyroid cancer vs. lobectomy?
- Removal any missed contralateral foci of cancer
- Use radioactive iodine scan to find/treat mets
- Use serum thyroglobulin as marker for recurrence
130
Which thyroid malignancy can be treated with thyroid lobectomy alone?
<1cm univocal papillary thyroid carcinomas
131
Who gets central lymph node dissection?
Medullary and papillary cancers
- Medullary: > 1cm
- Papillary: controversial
132
What is the role of intraoperative frozen section pathology?
- Diagnose papillary thyroid cancer
| - Show cancer in lymph nodes
133
Which thyroid cancer concentrate radioactive iodine?
Papillary and follicular
134
What is the follow-up procedure post-op for thyroid cancer?
- Measure thyroglobulin and anti-thyroglobulin Ab 2x a year
- 1x per year when stable
- Neck US annually
135
If recurrence of thyroid cancer is suspected, what study to perform?
Neck US with full lymph node survey
136
What non-op management is available for thyroid nodules?
- Radioactive ablation with iodine for hyper functioning nodules
137
What major structures can be injured during thyroidectomy?
- Recurrent laryngeal nerve
- External branch of superior laryngeal nerve
- Parathyroid glands
138
What prophylactic measure should be taken in patients with MEN-2A, 2B or FMTC?
Prophylactic thyroidectomy
139
What does thyroid tissue in the lateral neck represent in setting of thyroid cancer?
Metastatic papillary thyroid cancer in a lymph node
