DeVirgilio Pt III Flashcards
What do the symptoms of hypertension, headache, perspiration, palpitation, and pallor suggest?
Five P’s of hyperadrenergic syndrome (i.e. - pheochromocytoma). Pressure, pain, perspiration, palpitation, pallor.
What genetic conditions is pheochromocytoma associated with?
MEN 2 disorders (MEN 2A: Pheo, Medullary thyroid ca, primary HPT; MEN 2B: Pheo, Medullary thyroid ca, mucosal neuromas, marfanoid habitus)
Neurofibromatosis 1: Neurofibromas, cafe au lait, lis nodules.
von Hippel Lindau: Retinal angioma, CNS hemangioblastoma, renal cell cancer, PNET (pancreatic neuroendocrine tumor), pancreatic and renal cysts
What cells are involved in a pheochromocytoma and where are they located?
Chromaffin cells
Adrenal medulla or sympathetic ganglia
What hormones does a pheochromocytoma produce?
Norepinephrine-predominant catecholamines
Epinephrine concentration is lower than Nor-epi
What activities or events can trigger a hypertensive crisis in pheochromocytoma patients?
Changes in blood flow, physical stimulation, tumor necrosis, anesthetic agents, foods containing tyramine, surgical manipulation
What feature determines the malignancy of a pheochromocytoma?
Malignancy is based on local invasion and/or metastasis, not cellular features
How is pheochromocytoma diagnosed?
Urine and/or blood levels of catecholamines and metabolites,
CT or MRI with contrast is first line imaging
What is the most sensitive test for pheochromocytoma?
Plasma free metanephrine
Very sensitive but higher false positive rate
A negative test can therefor rule out pheo (if it were there, a highly sensitive test would find it), but a positive test must be confirmed with urine testing (low specificity = lots of false positives)
What additional imaging may be ordered for pheo and when should it be ordered?
Nuclear imaging with iodine-mataiodobenzylguanidine (I-MIBG) is highly specific
Useful in cases of suspected multifocal or extra-adrenal disease
What is the treatment for pheo?
Medical conditioning with alpha blockade for at least 2 weeks
Add beta-blockade for tachycardia and/or arrhythmia
Surgical resection is curative (laparoscopic if less than 8cm and no malignant features on imaging)
What are the catecholamines?
Epinephrine
Norepinephrine
Dopamine
Patient with unexplained, severe hypertension and tachycardia intra-operatively?
Think undiagnosed pheochromocytoma
What are the breakdown products of epinephrine, norepinephrine, and dopamine?
Epinephrine: Metanephrine and vanillylmandelic acid (VMA)
Norepinephrine: Normetanephrine and VMA
Dopamine: Homovanillic acid (HVA)
What are the surgically correctible causes of HTN?
95% of HTN is primary. 5% may be corrected surgically and result from:
pheo
adrenal adenoma producing cortisol or aldosterone
renal artery fibromuscular dysplasia
aortic coarctation
What are the normal and abnormal functions of a1 and a2 receptors?
a1: smooth muscle contraction, gluconeogenesis, glycogenolysis - abnormal fxn: hypertension and hyperglycemia
a2: Smooth muscle contraction, platelet aggregation - abnormal fxn: Pallor
What are the normal and abnormal functions of b1 and b1 receptors?
b1: Chronotropic, inotropic, sweat glands - abnormal fxn: tachycardia, sweating
b2: smooth muscle relaxation - abnormal fxn: hypotension
Why do pheos rarely produce dopamine and what happens when they do?
Specific catecholamine ratios are dependent on the location of the pheo, which can develop anywhere along the sympathetic nervous system. Dopamine secreting tumors are usually found in extra-adrenal (paragangliomas) which do not occur very often. Dopamine tumors do not produce hypertension, but do have watery diarrhea due to dopamine’s effect on the GI system
What to suspect in a patient with severe hypotension or hypoglycemia after bilateral adrenalectomy? Test?
Addisonian crisis.
Check plasma ACTH
How common are thyroid nodules and cancer? What are the risk factors for thyroid cancer?
Thyroid nodules are common, cancer is rare
Risk factors: female gender, ionizing radiation exposure, family history of thyroid cancer (MEN 2A, MEN 2B, FMTC)
What are the symptoms of hyperthyroid? Hypothyroid?
Hyper: nervousness, fatigue, weight loss. thirst. palpitations
Hypo: fatigue, weight gain, constipation, impaired cognition/libido
How are thyroid nodules worked up?
Most important: Initial TSH
All nodules eval’ed with U/S,
Nodule and High TSH = radioactive iodine scan
Iodine-avid, “Hot” nodules have low risk of malignancy
Indications for FNA of thyroid nodule?
> 1cm
Suspicious US findings
Increasing in size
Pathophysiology of thyroid cancer: Cells that make up thyroid?
Primarily Follicular cells - produce T3 T4 from thyroglobulin.
Small proportion of C cells - produce calcitonin
Pathophysiology of thyroid cancer: Papillary and follicular thyroid cancer cell types and differentiation? Prognosis of papillary ca?
Follicular cells
Well differentiated, majority take up iodine
Papillary cancer first spreads to lymphatics, but prognosis is based on the presence of local invasion.
Pathophysiology of thyroid cancer: Medullary thyroid cancer cell type? Symptoms of metastatic disease?
C cells
Diarrhea and flushing due to high calcitonin levels.
How to manage thyroid nodules: initial work up?
FNA is most important initial step.
Inadequate findings: repeat FNA
Benign findings: observe
How to manage thyroid nodules: AUS/FLUS findings? Malignant findings?
AUS/FLUS: repeat FNA
Malignant: total thyroidectomy, consider neck dissection
How to manage thyroid nodules: Suspicious for follicular neoplasm? Suspicious for malignancy?
Follicular neoplasm: diagnostic thyroid lobectomy
Suspicious for malignancy: total thyroidectomy
Associated morbidities of medullary thyroid carcinoma and what to do about them?
25% of patients have an underlying mutation. Pheochromocytoma must be excluded prior to surgery
Where is ectopic thyroid tissue usually found? What locations are concerning and where does it metastasize to?
Thyroid tissue may be found anywhere along the thyroglossal duct and in the anterior mediastimun.
Ectopic thyroid tissue in the lateral neck is usually cancerous and usually metastasizes to cervical lymph nodes
Major post-operative complications of thyroid surgery?
Numbness and tingling in the lips and fingers = likely hypoparathyroidism, promptly treat with oral calcium
Post-op neck swelling and stridor = hematoma compression the airway. Emergency bedside decompression!!
Common mutations in thyroid cancer
1/5 of papillary thyroid cancers are due to RET tyrosine kinase/papillary thyroid carcinoma rearrangements (RET/PTC)
1/3 or more have BRAF mutations. A signal transdutciton protein kinase
Most common cause of death in patients with thyroid storm? Tx?
high-output cardiac failure.
Tx: First line is beta-blockers and propylthiouracil
Which type of thyroid cancer cannot be evaluated with FNA?
Follicular thyroid cancer is considered malignant only if it has breached the capsule, not by cytology. FNA will not show if the cells have breached the capsule.
What cancers have psammoma bodies?
Papillary thyroid Serous cystadenocarcinoma of the ovary Meningioma Mesothelioma PSaMMoma
How do the three types of thyroid cancer spread and what does this mean for biopsy?
Papillary and medullary cancers spread lymphatic ally, and lymph node biopsy is useful
Follicular cancers spread hematogenously, therefor no lymph node biopsies are needed
Post-op management of Thyroid cancer?
Radioactive iodine ablation: I131 may reduce the recurrence and increase survival in follicular and a subset of papillary tumors.
Suppressive thyroxine: TSH stimulates the growth of thyroid tissue, use Levothyroxine to suppress TSH
Serum thyroglobulin: Can be monitored as an indicator of recurrence in patients who have had a total thyroidectomy. Baseline, 6 mo, 12 mo, and annually afterward.
Serum Calcitonin: Should be monitored for medullary carcinoma
Workup for recurrent cancer found by increased Tg levels?
1st: Neck ultrasound for biopsy-able masses
2nd: if no masses, I131 scan or thin cut, non-contrast CT
Possible complications of thyroid surgery?
Injury to recurrent laryngeal nerve (hoarseness with unilateral, airway obstruction if bilateral = urgent tracheostomy)
Injury to external branch of superior laryngeal nerve (nerve permits high pitched speaking or singing)
Parathyroid de-vascularization, if permanent = calcium and calcitriol supplements
Hoarseness: What is the most common type of laryngeal cancer? Most common site of malignant lesions of the larynx?
Squamous cell carcinoma
The glottis
Hoarseness: Other common laryngeal neoplasia? Cause?
Laryngeal papilloma, aka recurrent respiratory papillomatosis. Caused by HPV 6 and 11. May rarely give rise to laryngeal carcinoma.
Hoarseness: What is the common presentation and risk factors for laryngeal carcinoma?
Duration, Progression, and quality of hoarseness
Significant history of tobacco smoking or chewing
Alcohol use compounds tobacco use (not a risk factor in absence of tobacco)
Hoarseness: What is the workup for laryngeal carcinoma?
Indirect laryngoscopy in office or direct laryngoscopy in the OR under sedation - rule out vocal cord paralysis, spasmodic dysphonia, or nodules/polyps/cysts
Chest X-ray - rule out primary concurrent primary lung cancer or metastases (smoking association as well as lungs are the most common location for head/neck squamous cell carcinoma metastases)
CT of the neck - metastases to neck lymph nodes, not always ordered for early stage carcinomas
TNM staging
Difference in treatment between early stage (I and II) and late stage (III and IV) laryngeal cancers?
Early stage: Single modal therapy, surgery or radiation, is usually effective
Late stage: Bi or Tri-modal therapy, surgery, radiation, chemotherapy, is often required. Neck dissection is required in patient with suspected or known metastases.
Primary goal in treating laryngeal cancer?
Preservation of the larynx