Endocrine Flashcards
Adrenal incidentaloma screening test for function.
1) overnight dexamethasone suppression test
2) Serum urine catecholamines & metanephrines
3)Aldo/renin ratio
Adrenal incidentaloma imaging feature of cancer
- larger than 4cm
- irregular inhemogenous morphology
- delayed contrast washout
- Greater than 20 HU
Pituitary gland incidentaloma
<10mm “microadenoma”
If there are no clinical features of pituitary hormonal hyperfunction, then the most cost effective strategy is to measure only prolactin levels.
Small lesions (2-4 mm) require no further testing, while lesions 5-9 mm usually require follow-up MRI in 12 months to document a lack of growth
Pituitary gland incidentaloma
>10mm “macroadenoma
Lesions > 10 mm should be evaluated with biochemical testing for both pituitary hormonal hyperfunction/hypofunction (e.g., Cushing’s, acromegaly, and prolactin) and formal visual field/acuity testing
Lesions without mass effect or hormonal dysfunction can be safely followed with periodic clinical, biochemical, and radiological evaluation
Pituitary gland incidentaloma surgery indication
Surgery is considered for macroadenomas with hormonal dysfunction or tumor mass effect, except for prolactinoma where medical therapy is effective.
Diabetic amyotrophy
-occurs in reasonably controlled diabetics. May not have other diabetes complications
Presentation:
1)Acute asymmetric focal onset of pain followed by weakness in the proximal leg
2) autonomic failure
3)greater than 10% weight loss
Thyroid function post RAI
TSH remains suppressed for months after radioactive iodine ablative treatment. Further treatment decisions are based on total T3 and free T4 levels, patient symptoms, and clinical examination.
Opioid related hypogonadism
Chronic opioid use leads to decreased gonadotropin-releasing hormone secretion, and is a common cause of hypogonadism. Patients can develop decreased libido and other manifestations of hypogonadism. Management options include discontinuation, dose reduction, or rotation of opioid types, or androgen replacement therapy.
Hungry bone syndrome
Risk factors for developing hungry bone syndrome after parathyroidectomy include moderate-to-severe hyperparathyroidism with evidence of high bone turnover, older age, and renal dysfunction. Laboratory findings include low calcium, low phosphorus, low magnesium, and normal (or high) PTH levels.
Levothyroxine in central hypothyroidism
Levothyroxine therapy in central hypothyroidism should be based on serum free T4 levels, with the dose adjusted to maintain T4 in the high-normal range. TSH in central hypothyroidism demonstrates minimal responsiveness to levothyroxine and may not rise in patients with inadequate replacement.
Thyrotoxicosis with low RAI uptake
1)Painless thyroiditis (silent thyroiditis, lymphocytic thyroiditis, subacute lymphocytic thyroiditis & postpartum thyroiditis)
2)Subacute (de Quervain’s) thyroiditis (subacute granulomatous thyroiditis)
3)latrogenic (eg, lithium, amiodarone, iodine, interferon alpha, interleukin-2)
4)Factitious ingestion of levothyroxine (T4) &/or triiodothyronine (T3)
5)Struma ovari
6)Acute thyroiditis
7)Extensive thyroid cancer metastases
Laryngospasm post thyroidectomy DDX
Laryngospasm causing inspiratory stridor after thyroidectomy is a medical emergency.
The timing of stridor after thyroidectomy can provide a clue to its cause.
A) If respiratory distress or stridor is apparent immediately upon extubation, bilateral recurrent laryngeal nerve injury is likely.
B) Stridor appearing within a few hours of surgery suggests possible wound hematoma with tracheal compression
C) Stridor appearing later, especially if preceded by paresthesias or muscle cramps, suggests hypocalcemia from transient hypoparathyroidism or inadvertent parathyroidectomy.
HbA1c pitfalls
Hemoglobin A1c is vulnerable to changes in hemoglobin production and survival;
Conditions associated with reduced red blood cell survival (eg, hemoglobinopathies) can cause a misleadingly low A1c,
Conditions associated with reduced red blood cell production (eg, iron deficiency) cause a misleadingly high Alc.
In such cases, the underlying hematologic condition should be corrected and the Alc rechecked. Alternately, serum fructosamine, which measures glycation of serum proteins, can be ordered; this test estimates glycemic control over 6-8 weeks
When to treat subclinical hypothyroidism
1) TSH greater than 10
2) Positive Anti-TPO
3) Goiter
4) Symptomatic
5) Pregnancy
6) Ovulatory dysfunction with infertility
7) Hypercholesterolemia
Hypothyroidism and heart
Initial work-up of patients with chronic pericardial effusion includes a complete blood count, basic metabolic panel, thyroid function tests, anti-double stranded DNA antibodies, and complement levels
Hyperthyroidism in elderly
Hyperthyroidism may present with apathy in older individuals. Shortness of breath, weight loss, and atrial fibrillation occur more commonly in older patients. Screening for hyperthyroidism should be done in older individuals presenting with new onset atrial fibrillation.
Paget disease
Paget disease of bone can be asymptomatic or present with bone pain. Diagnosis is confirmed by radiographic abnormalities and elevated bone alkaline phosphatase. Bone scan can delineate the extent of disease and guide treatment. Bisphosphonates are the preferred treatment
Statin side effects
Statins are associated with an increased risk of diabetes mellitus and worsening glycemic control in patients with established diabetes mellitus. However, this excess risk is significantly less than the reduction in risk for cardiovascular events
Toxic adenoma and toxic multi nodular Goiter treatment
Patients with toxic adenoma or multinodular goiter who have overt hyperthyroidism (low TSH, increased T4) should have definitive treatment with radioactive iodine ablation or surgical thyroidectomy, rather than only symptomatic management
Unlike Graves disease, in which radioiodine ablation leads to postablative hypothyroidism, the radioactive iodine in nodular thyroid disease is taken up primarily in the abnormal tissue, with little damage to the surrounding healthy tissue. Following treatment, most patients are euthyroid
Diabetes test discrepancy
The diagnosis of diabetes or prediabetes requires two abnormal test results from the same sample or in two separate test samples; when there is a discrepancy in screening test results, the abnormal test should be repeated.
Hypogonadism in obese patients
In male patients with obesity, hypogonadism is best diagnosed by a free testosterone assessment because the total testosterone level may be affected by a decrease in the sex hormone–binding globulin level.
Chronic hypoparathyroidism
In chronic hypoparathyroidism, the goals of therapy are to eliminate symptoms while avoiding complications of therapy; monitoring urine calcium excretion is mandatory because hypercalciuria often limits therapy.
Autoimmune polyglandular syndrome type 1
Autoimmune polyglandular syndrome type 1 is an inherited autosomal recessive disorder characterized by chronic mucocutaneous candidiasis, autoimmune hypoparathyroidism, and adrenal insufficiency.
Autoimmune polyglandular syndrome type 2
Autoimmune polyglandular syndrome type 2 is associated with adrenal insufficiency (100%), chronic autoimmune thyroid disease (but occasionally Graves disease), type 1 diabetes mellitus, primary hypogonadism, and diabetes insipidus.
