Surgical Management of Endocrinopathies Flashcards
Gastrinoma
- Pres: Many peptic ulcers, unusually distal peptic ulcers, or peptic ulcers refractory to PPIs
- Dx: Elevated gastrin (must be taken off of PPIs) for screening. If gastrin in 4 digits, it is cancer. If it is more mildly elevated, confirm diagnosis with secretin challenge (should turn off healthy gastrin, in cancer gastrin elevates instead). Somatostatin receptor scintillography to locate tumor.
- Tx: Resect
- Note: We don’t cut it out because it is milignant, we cut it out because #1 it causes refractory PUD and #2 it can produce other gastric cancers that are malignant.
Insulinoma
- Dx: Wait for quantitative or symptomatic hypoglycemia, then draw labs: insulin, c-peptide, and sulfonylurea screen. If insulin and c-peptide are elevated, you have your diagnosis. Follow-up with CT scan for localization and staging.
- Tx: IV glucose after taking diagnostic bloodwork. Surgical resection.
“Migratory necrolytic dermatitis”
Glucagonoma buzz word
Primary hyperparathyroidism
- Presentation: Elevated Ca, low phos, may present w/ osteofibrosis cystica (aka Brown tumor) and/or bone pain
- Dx: Sestanibi scan (to tell you which parathyroid is hot)
- Tx: Cut it out. Then, carefully monitor Ca post-operatively, since other parathyroids may take time to recover. Give IV calcium when necessary until parathyroids recover.
Thyroid nodule management algorithm
Note: If first FNA indeterminate, wait 6-12 weeks and repeat (to avoid false positives from reactive changes caused by first FNA)
Parathyroid autofluorescence
- Parathyroid glands possess a unique autofluorescence in the near-infrared spectrum (~820 nm emission)
- Can be visualized via: Storz laparoscopic near-infrared/indocyanine green (NIR/ICG) imaging system with minor modifications to the xenon light source (filtered to emit 690 nm to 790 nm light, less than 1% in the red and green above 470 nm and no blue light)
- Post-processing may be utilized to enhance the signal to noise ratio on the display and improve detection
Follicular adenoma vs follicular carcinoma
- Follicular adenoma is a benign thyroid nodule
- They are quite common in adults
- Unfortunately, they cannot be differentiated from follicular carcinoma on the basis of cytology (aspiration) alone. This requires a core needle biopsy showing architecture.
- Note: The same is true of Hurthle cell adenoma vs carcinoma
MEN syndromes
Thyroid nodules greater than ___ in size are clinically significant and require further evaluation
Thyroid nodules greater than 1 cm in size are clinically significant and require further evaluation
If a biopsy result for thyroid mass returns as medullary thyroid cancer, the next step is. . .
. . . MEN2 testing
If MEN2 testing is positive, urine metanephrines should be run to screen for pheochromocytoma. If present, this cancer takes precidence and should be dealt with prior to the medullary carcinoma.
If a patient’s FNAB results are nondiagnostic, the next step is to. . .
. . . try FNAB again!
Repeat biopsy will obtain an adequate specimen the second time in 50% of cases
If this second biopsy failed, the surgery is recommended.
Routine tests performed in a patient with a thyroid nodule who is clinically euthyroid
TSH and FNA biopsy
The presentation of multiple subcentimeter cystic nodules in the thyroid is. . .
. . . common, typically seen in women
These are probably macrofollicles. They can be safely observed with serial ultrasound if TSH is normal.
Most important risk factor for thyroid cancer
History of head/neck irradiation
GREATLY increases odds that any thyroid nodule is cancerous
MEN2 A or B is also an important risk factor.
Role of thyroid uptake scan
Principally used in the scenario of nodule + hyperthyroidism
Initial step in treatment of a thyroid neoplasm after diagnosis
Diagnostic thyroid lobectomy
This is necessary for local staging, which cannot be determined by FNA
Chloride phosphate ratio
Cl : Phos > 33 : 1 suggests hyperparathyroidism
Diagnosis and management of FHH
Diagnosis is by demonstrating elevated PTH in the context of low urinary calcium plus family history
Management is. . . nothing. It is a benign condition.
Parathyroid hyperplasia vs parathyroid adenoma
Parathyroid adenoma is one hot nodule.
Parathyroid hyperplasia involves all four parathyroids.
PTH on renal electrolyte handling
PTH increases the excretion of phosphate and bicarb
To maintain electrical neutrality, more chloride is reabsorbed
Hence, elevated chloride : phosphate ratio
Hypercalcemia of malignancy vs primary hyperparathyroidism on electrolytes alone
Primary hyperparathyroidism is associated with elevated chloride, while hypercalcemia of malignancy (ectopic 1 alpha hydroxylase) is not.
Both produce hypercalcemia and can produce hypophosphatemia.
Most common metabolic complication of primary hyperparathyroidism
Kidney stones!
~1/5 of patients with primary hyperparathyroidism present this way
While primary hyperparathyroidism is the #1 cause of hypercalcemia in the general outpatient population, ___ is the #1 cause of hypercalcemia in hospitalized patients.
While primary hyperparathyroidism is the #1 cause of hypercalcemia in the general outpatient population, malignancy is the #1 cause of hypercalcemia in hospitalized patients.
Surgical management of parathyroid hyperplasia
Total parathyroidectomy with reimplantation (of 1/2 gland)
OR
Subtotal parathyroidectomy
Surgical management of parathyroid carcinoma
En-bloc ipsilateral removal of with thyroid lobectomy and excision of involved soft tissue
Types of acquired parathyroid disease that can cause hypercalcemia
- Primary hyperparathyroidism
- Tertiary hyperparathyroidism
- Parathyroid hyperplasia
- Parathyroid carcioma
- While most thyroid cancers do not secrete thyroid hormone, most parathyroid cancers do secrete PTH
R and L adrenalectomies are. . .
. . . completely different surgeries
Which surgery is higher risk? R or L adrenalectomy?
R, because if you accidentally nick the adrenal vein or IVC, the IVC will pour blood into the abdomen
Mnemonic for zones of the adrenal gland
GFR
Granulosa, fasciculata, reticularis
Up to __ of adrenal incidentalomas are functional
Up to 1/3 of adrenal incidentalomas are functional
Any adrenal incidentaloma ____ needs an evaluation – unless it is ___.
Any adrenal incidentaloma > 1 cm needs an evaluation – unless it is an obvious myelolipoma (fatty on imaging).
Best rule out test for Cushing’s
1 mg dexamethasone suppression test
Take pill at 11:00, come in for blood test next morning
Then follow with high dose supression test if positive
Assessment of physiologic derangements in Cushing’s
Best rule out test for Conn’s
Renin:aldosterone ratio
> 30 indicates positive screening
Can’t be measured while on mineralocorticoid receptor antagonists
Pheochromocytoma testing
Rule out with plasma metanephrines (> 2x normal is positive)
If positive, confirm with 24 hour urinary metanephrines
Adrenocortical carcinoma
- Poor prognosis
- No biochemical markers to detect malignancy – criteria for cancer based on imaging findings
- < 4 cm, can monitor, low risk malignancy
- > 4 cm, higher risk malignancy, remove by open adrenalectomy
You should NEVER biopsy a patient with an adrenal mass without ruling out. . .
. . . pheochromocytoma
Pheochrocytoma rule of 10’s
Unlike most adrenal masses, pheochromocytomas are ___ on MRI
Unlike most adrenal masses, pheochromocytomas are T2 bright on MRI
Since they are so vascular
When the diagnosis of pheochromocytoma is made
- If on a beta blocker, stop it
- Want to alpha block first
- Put on phenoxybenzamine (alpha blocker)
In the case of hyperaldosteronism, many patients with adrenal nodule. . .
. . . have an incidental adrenal nodule and a non-surgical source of hyperaldosteronism
Might be bilateral hyperplasia, might be familial syndrome, might be myofibrosis, etc.
Risks for poor improvement of hyperaldosteronism with surgery on adrenal aldosteronoma
- Male
- Old
- Overweight
Diagnosis of a gastrinoma
Secretin stimulation and serum gastrin measurement
Pancreatic neuroendocrine neoplasm syndromes
- Insulinoma: Refractory hypoglycemia with high C peptide and no history of sulfonylurea use.
- Gastrinoma: Refractory peptic ulcer disease and a metabolic alkalosis
- Glucagonoma: Diabetes, stomatitis, anemia, and necrolytic migratory erythema
- VIPoma: Watery diarrhea, hypokalemia, achloyhydria
- Somatostatinoma: Steatorrhea, cholelithiasis, and diabetes
Patient presents with new onset weakness. Weakness is increased upon repetitive motion. What are you likely to find on imaging of this patient?
A thymoma
This patient has myasthenia gravis, and 50% of patients with myasthenia gravis have a thymoma, and thymectomy improves MG symptoms in up to 60% of patients with myasthenia gravis
Most common anterior mediastinal mass by age and gender
Women under age 40: Hodgkin’s and Non-Hodgkin’s lymphoma
Men under age 40: Non-seminomatous germ cell tumors, followed by Hodgkin’s and Non-Hodgkin’s lymphoma
Over age 40: Thymoma
Tumor markers for male germ cell malignancies
Seminomas tend to be relatively tumor marker poor, while nonseminomatous germ cell tumors having significantly elevated tumor markers (AFP, beta-HCG)
Rather than having tumor markers, seminomas often present with anterior mediastinal mass, so imaging should be performed if suspected.
Substernal goiters
Thyroid goiters that extend from cervical goiter (or rarely originate in the mediastinum) may present as anterior mediastinal masses
Those which develop de-novo in the mediastinum often have bloodflow directly from the aortic arch and are highly vascular, while those that extend from above are supplied by the typical thyroid vessels.
Posterior mediastinal tumors
~15% of mediastinal masses in adults, but ~50% in children
Often of neurogenic origin
Middle mediastinal masses
Often associated with lymphoproliferative disorders such as lymphoma or Castleman’s disease
Thymectomy in non-thymomatous myasthenia gravis
Utility still unclear.
Some of these patients have thymic hyperplasia on post-surgcial pathology and it is believed that they may benefit. Modest benefits have been shown for certain populations, particularly young female patients with mild disease, however the evidence is not high quality.
Diagnosis and treatment for common mediastinal masses
Staging of thymomas
Based upon surgical pathology of margins. As such, surgical resection is necessary for tumor staging and cannot be done prior to surgery.
Diagnosis of mediastinal mass
FNAs are often preformed first, but are unlikely to yield diagnosis.
Diagnosis is usually made at the time of surgery or based on surgical pathology.
Thymoma paraneoplastic syndromes
- Myasthenia gravis
- Red cell dysplasia
- Immunodeficiency (Good’s syndrome w/ hypogammaglobulinemia)
- Collagen vascular disease
- These are often not resolved with thymectomy
Aldosterone and cortisol producing lesions require ___ in order to confirm the utility of surgical resection
Aldosterone and cortisol producing lesions require hormone lateralization studies in order to confirm the utility of surgical resection
Utility of PET scan in evaluation of an adrenal mass
In someone with known metastatic disease, PET can tell you whether an adrenal mass is primary adrenal or a metastasis
Etiologies of adrenal incidentaloma that can be ruled out based on CT criteria alone
- Myelolipoma
- Cyst
- Hematoma
Criteria for adrenalectomy
- Any functional adrenal tumor
- Nonfunctional adrenal tumors > 4 cm
- Adrenal tumors that grow by 0.8 cm or more over 1 year
- Tumors with imaging characteristics suspicious for adrenocortical carcinoma
- Irregular margins, heterogeneous density, scattered areas of deattenuation, local invasion
- Suspected oligometastatic disease to the adrenal gland
Recommended management for adrenal incidentalomas < 4.0 cm that are proven nonfunctional and nonmetastatic
- Repeat imaging at 3 months and again at 15 months
- Increase in size by 1 cm is an indication for prompt adrenalectomy
- In the absence of change during this period, follow annually with history, physical exam.
- Repeated biochemical testing is reserved for the context of abnormal historical or physical findings
Plasma vs urine metanephrines
Plasma is more sensitive, but less specific than urine metanephrines
When you have an adrenal mass and you are not sure whether or not it is a pheochromocytoma after CT and metanephrines, what can you do?
I-131 metaiodobenzylguanidine scan
Used for confirmation or evaluation of nonlocalized pheochromoctyomia. Has specificity of 90-100% for pheos, but is not entirely sensitive.
Perioperative evaluation and management for pheochromoctyoma
- CXR (pheos often metastasize to the lungs)
- EKG and Echo (to rule out cardiomyopathy secondary to chronic catecholamine excess)
-
Manage catecholamine balance:
- Take off of beta blocker if already on one
- Add alpha blocker at least 2 weeks prior to surgery (phenoxybenzamine is preferred)
- Add alpha-methyl-p-tyrosine (competitive inhibitor of tyrosine hydroxylase)
- Add back additional beta blockade if necessary
Intraoperative hemodynamic management of a patient with pheochromocytoma
- They come in already on phenoxybenzamine and alpha-methyl-p-tyrosine
- Continuous IV nitroprusside drip to control hypertension
- Esmolol (short acting beta blocker) as needed to control tachycardia
- After excision when hypotension ensues, continuous IV norepinephrine when fluids are insufficient
If a serum metanephrine level comes back mildly elevated, the next step is. . .
. . . 24 hour urine metanephrine, normetanephrine, and VMA to confirm elevation.
PEDIS for evaluation of diabetic foot wounds
- Perfusion
- Extent
- Depth
- Infection
- Sensation
Initial empiric workup for classic uncomplicated diabetic foot ulcer
- Wound culture
- Blood culture
-
Empiric antibiotics covering Staph aureus and GAS
- Pseudomonas as well if necrotic or blue-tinged wound
- 7-14 day course is recommended in absence of osteomyelitis
- 4-6 weeks if osteomyelitis present
- Bed rest
- Glycemic control
-
Local wound care:
- Sharp debridement
- Larval therapy
- Topical agents
Motor neuropathy and autonomic neuropathy in diabetic foot disease
In addition to the effects of sensory neuropathy, motor and autonomic neuropathy may contribute to the development of diabetic foot ulcers
Imbalance between flexor and extensor groups may cause resting foot deformities or poor fine motor control which increases vulnerability to injuries.
Autonomic neuropathy may cause loss of sweat gland function, skin cracking, soft tissue edema, and osteopenia.
Any wound with a visible biofilm generally requires ___
Any wound with a visible biofilm generally requires debridement
Bunion
- aka Hallux valgus
- Enlargement of the bony tissue at the base of the big toe
- Generally associated with angulation of the first toe toward the other toes.
- Usually in women and related to wearing tight, pointed, confining shoes.
- Predisposes to injuries in the overlying skin and soft tissue.
Hammertoe
- Contracture of the toes (often sparing the big toe)
- Upward bend of the second to fifth toes at the metatarsal-proximal phalangeal joint
- Downward bend of the distal toes
- Produces “clawed toes”
- Deformity occurs uniformly in women and is due to muscle-tendon imbalance produced by tight shoes with heels
Charcot foot
- Type of neuropathic osteoarthropathy
- occurs mostly in diabetic patients
- Often difficult to differentiate from diabetic foot infection with osteomyelitis
- Neurally mediated vascular reflex causes inflammation, increases blood flow and metabolic cahnges in bones in the foot/ankle
- Risk for fractures and soft tissue trauma
- Late-stage disease produces “rocker-bottom” deformity (pictured)
- Treatment involves offloading
Offloading
Form of treatment strategy for Charcot foot
Affected foot is immobilized in a contact cast to rest injuries and prevent progression of injuries to permanent deformity
Diabetic foot ulcers at the tips of the toes are likely to be ___ in origin.
Diabetic foot ulcers at the tips of the toes are likely to be vascular in origin.
Diabetic foot disease screening by risk stratification
- Low risk: Intact sensation and pulses. Annual exams.
- Moderate risk: Neuropathy OR absent pulses. Exams every 3-6 months.
- High risk: Anything more than the above or history of prior ulcers. Exam every 1-3 months.
If you suspect that a diabetic foot ulcer may involve osteomyelitis, you should preform ____ for diagnosis
If you suspect that a diabetic foot ulcer may involve osteomyelitis, you should preform a gallium scintigraphy scan for diagnosis
Gallium-67 is a radionuclide that binds to acute phase reactants such as transferrin and accumulates in areas of infection and inflammation.
Signs of deep space infection in diabetic foot ulceration
- Pain
- Swelling
-
Wound drainage
- The above are all indications for imaging studies/wound exploration in the appropriate clinical context
Claudication in a diabetic patient
May be absent as a clinical indicator of peripheral arterial disease due to diabetic neuropathy!
Therefore, these patients should have screening ABIs or toe-brachial indices at every visit. Keep in mind that these may be falsely elevated due to arterial calcifications.
ABI and chronic ulcers
In the setting of PAD with ABI less than 0.5, it is highly unlikely that a chronic foot ulcer distal to the involved vessel will heal without revascularization.
If revascularization is not an option, amputation may be required.
Recurrent diabetic foot ulcers after antibiotic therapy are highly likely to be ___, even if the first was not.
Recurrent diabetic foot ulcers after antibiotic therapy are highly likely to be polymicrobial, even if the first was not.
So if the first one got better with vancomycin, you still have to pull out broad spectrum antibiotics (piperacillin-tazobactam) when it comes back.
Brown tumor
- Bone lesion that arises in settings of excess osteoclast activity, such as hyperparathyroidism
- Consists of mostly fibrous tissue with a high degree of hemosiderin
- The high level of hemosiderin colors the tumors brown, hence the name
- They are a form of osteitis fibrosa cystica
- Most commonly affects the maxilla and mandible, though any bone may be affected
- Associations:
- Hyperparathyroidism
- ESRD osteodystrophy
Carcinoid syndrome
- Hallmarks:
- Episodic flushing
- Secretory diarrhea
- Cutaneous telangiectasias
- Bronchospasm
- Tricuspid regurgitation
- Pathophysiology:
- Tumor (usually in terminal ileum, colon, or lung) that secretes histamine, serotonin, or VIP.
Milk-Alkali syndrome
- Hypercalcemia symptoms: Abdominal pain, constipation, polydipsia
- Due to excessive intake of calcium and absorbable alkali
- Hypercalcemia causes renal artery vasoconstriction and nephrogenic diabetes insipidus
- This may be so severe as to cause AKI
- Often in patients being treated for osteoporosis
Extra-osseus manifestations of Paget’s disease
- All due to bone growth/obstruction
- Headaches
- Cranial nerve palsies
- Hearing loss (involvement of ossicles)
Paget’s disease on CXR
- May present with osteolytic lesions or mixed osteolytic-osteoblastic lesions, but NEVER osteoblastic lesions
Addison’s is sometimes associated with ___ on blood labs
Addison’s is sometimes associated with normocytic anemia and eosinophilia on blood labs
Labs in Paget’s disease
- High ALK
- High urine hydroxyproline
- Relatively normal calcium and phosphate
Labs in osteomalacia
- PTH will be high
- Calcium can be low OR normal
- Phosphate will be low
- Vitamin D will be low
Hurthle cells
Cells found among follicular thyroid cancer OR instead of typical follicular cells (as a subtype of follicular carcinoma)
The cells are large and highly “oxyphilic”, with copious eosinophilic cytoplasmic granules. They also have prominent nucleoli.
Medullary thyroid cancer histology
- Stroma contains large amounts of amyloid, and thus stains with Congo red
- Neuroendocrine appearance with packages of uniform cells
Thyroid storm
- Goiter, tremors, and lid lag are specific features
Bethesda classification
Another name for “euthyroid sick syndrome”
Low T3 syndrome
Basically describes the main abnormality
Mutations that are basically 100% for thyroid malignancy
BRAF-V600E mutation (differentiated thyroid cancer)
RET (medullary thyroid cancer)
