Dr. Midha
Dr. Dombrowski
Dr. Morocco
Dr. Ciltea
Dr. HbA1c
100
A 49-year-old woman has had increasing cold intolerance, weight gain of 4 kg, and sluggishness over the past two years. A physical examination reveals dry, coarse skin and alopecia of the scalp. Her thyroid is not palpably enlarged. Her serum TSH is 11.7 mU/L with thyroxine of 2.1 micrograms/dL. A year ago, anti-thyroglobulin and anti-microsomal autoantibodies were detected at high titer. Which of the following thyroid diseases is she most likely to have? .............................. A. DeQuervain disease B. Papillary carcinoma C. Hashimoto thyroiditis D. Nodular goiter E. Graves disease
Answer: C. Hashimoto thyroiditis is the most common cause for hypothyroidism in adults. Though the thyroid may initially have been painlessly enlarged, over time the inflammation leads to atrophy of the thyroid with hypothyroidism. Anti-thyroid autoantibodies are helpful in establishing the diagnosis. Subacute granulomatous thyroiditis (DeQuervain disease) leads to transient thyroid enlargement with pain, but the course runs for a month or two and patients typically do not become hypothyroid. Carcinomas of the thyroid are not typically associated with autoantibodies. A nodular goiter is rather inert, as thyroid lesions go. Graves disease produces hyperthyroidism and thyroid enlargement. Removal of the thyroid as treatment can lead to hypothryoidism.
100
Patient comes in reporting that she takes 25 units of U500. How much insulin is she taking and how would you write the order?
The patient is taking 125 units of insulin and the order is 0.25ml U500 Insulin
100
A thyroid RAIU and scan is performed, which shows absent iodine uptake throughout the thyroid gland. A serum thyroglobulin level is undetectable. What is this patient’s most likely diagnosis? .............................. A. Exogenous thyrotoxicosis B. Graves’ disease C. Hashimoto’s thyroiditis D. Toxic multinodular goiter
Answer: A. Exogenous thyrotoxicosis. Exogenous thyrotoxicosis refers to excessive thyroid hormone from an extrathyroidal source. Specifically, thyrotoxicosis factitia describes thyrotoxicosis that is a result of excessive ingestion of thyroid hormone. The herbal weight loss supplement that this patient was taking was found to contain both T3 and T4. Patients with exogenous thyrotoxicosis can present similarly to those with hyperthyroidism from other causes. Results of this patient’s RAIU and scan demonstrate that both Graves’ disease and toxic multinodular goiter are unlikely, as increased uptake in a homogenous or heterogeneous pattern, respectively, would be expected. The serum thyroglobulin level may help differentiate between endogenous (associated with elevated thyroglobulin) and exogenous (associated with decreased or undetectable thyroglobulin) hyperthyroidism. Hashimoto’s thyroiditis is typically not associated with symptoms of thyrotoxicosis
100
A 28-year-old woman has had difficulty concentrating at work for the past month. She is constantly getting up and walking around to visit co-workers. She complains that the work area is too hot. She seems nervous and often spills her coffee. She has been eating more but has lost 5 kg in the past 2 months. On physical examination her temperature is 37.5 C, pulse 101/minute, respiratory rate 22/minute, and blood pressure 145/85 mm Hg. Which of the following laboratory findings is most likely to be present in this woman? .............................. A. Decreased catecholamines B. Decreased iodine uptake C. Decreased plasma insulin D. Decreased TSH E. Increased ACTH F. Increased calcitonin
Answer: D. There are both thyroid-stimulating immunoglobulins (TSI) and thyroid growth-stimulating immunoglobulins (TGI) in Graves disease that produce hyperthyroidism. The amount of thyroid hormone production goes up, suppressing TSH secretion from the pituitary. Some of her symptoms such as hypertension, could be consistent with an excess of catecholamines, not a decrease. The iodine uptake is increased with the hyperfunctioning thyroid of Graves disease. She has findings that suggest hyperthyroidism, not diabetes mellitus. Her symptoms are not related to Cushing syndrome or Cushing disease, but to Graves disease. Calcitonin may be increased with medullary thyroid cancers, but is not with Graves disease.
100
Which one of the following can contribute to serum calcium elevation? (check one) .............................. A. Furosemide (Lasix) B. Verapamil (Calan, Isoptin) C. Enalapril (Vasotec) D. Hydrochlorothiazide E. Allopurinol (Zyloprim)
What is D. Hydrochlorothiazide While thiazide diuretics do not cause hypercalcemia by themselves, they can exacerbate the hypercalcemia associated with primary hyperparathyroidism. Thiazides decrease the renal clearance of calcium by increasing distal tubular calcium reabsorption. Furosemide tends to lower serum calcium levels and is used in the treatment of hypercalcemia. None of the other medications would be expected to significantly affect the serum calcium level in this patient.
200
A 38-year-old man experiences abdominal pain, nausea, and constipation for the past 3 days. On physical examination he has no palpable abdominal masses and bowel sounds are present. His lungs are clear to auscultation. He has a heart rate of 80 with an irregular rhythm. An electrocardiogram demonstrates a shortened QT(corrected) interval and a prolonged PR interval. He has a stool positive for occult blood. Upper GI endoscopy reveals multiple 1 cm diameter shallow ulcerations of the gastric antrum. Which of the following laboratory test findings is most likely to be present in this man? .............................. A Thyroid peroxidase antibody of 4 IU/mL B. Serum calcium of 12.4 mg/dL C. Blood glucose of 225 mg/dL D. Total serum thyroxine of 21 ng/mL E. Plasma cortisol of 45 microgm/dL at 8 am F. Urine normetanephrine of 692 microgm/gm of creatinine G. Plasma renin activity (upright) of 6.8 ng/mL/hr
Answer: B. He most likely has a parathyroid adenoma secreting excessive parathormone to increase serum calcium and decrease serum phosphorus. The hypercalcemia leads to increased gastrin production and peptic ulcer disease. Hypercalcemia produces cardiac arrhythmias (or asystole). A positive anti-TPO suggests an autoimmune process such as Hashimoto thyroiditis. C is incorrect because Graves disease can be associated with a thyroxine level this high. D is incorrect because Graves disease can be associated with a thyroxine level this high. Pituitary adenomas secreting ACTH (or an ectopic source of ACTH) to produce adrenal hyperplasia, or adrenal neoplasms, can cause secretion of excessive cortisol. Increased urinary catecholamines are seen with pheochromocytoma, which can be associated with hypertension but not gastric ulcerations. Hyperreninemia may be seen with some forms of renovascular hypertension and with hyperaldosteronism with hypokalemia.
200
A 33-year-old woman presents to the clinic with a positive home pregnancy test. The patient has a history of Hashimoto’s thyroiditis, which has been successfully managed with levothyroxine 125 µg daily for the past 4 years; serum thyroid-stimulating hormone (TSH) level is check and is 2.75 µIU/mL (normal, 0.3-5.5 µIU/mL). She has a family history of thyroid disease, and her mother also takes levothyroxine. In the office, the pregnancy test is confirmed; this is her first pregnancy. To remain biochemically and clinically euthyroid, how should this patient be managed? .............................. A. Levothyroxine should be increased B. Levothyroxine should be decreased C. Triiodothyronine (T3) should be taken in addition to levothyroxine D. The pregnancy should be terminated
Answer: A. Levothyroxine should be increased. During the first trimester of pregnancy, serum estradiol concentration increases and the amount of thyroxine-binding globulin approximately doubles. Thus, an increase in total T4 is required to maintain free T4 within normal range. Human chorionic gonadotropin from the placenta typically stimulates the thyroid to increase production of T4. However, women with primary hypothyroidism cannot keep up with the increased demands on the thyroid during pregnancy, often resulting in maternal hypothyroxinemia in the first trimester, which may lead to impaired intellect and cognition in offspring. Hypothyroidism can be safely treated during pregnancy with levothyroxine. Levothyroxine dose should be increased by about 30% to 50% early in the first trimester in order to maintain serum TSH concentration between 0.5 and 2.0 µIU/mL and serum free T4 concentration within the upper third of normal. There is no role for treatment with T3 during pregnancy.
200
A 65-year-old man returns to the clinic 3 months after routine blood tests revealed a serum TSH level of 0.08 µIU/mL. The patient has been feeling well and denies cold or heat intolerance, palpitations, diarrhea, neck pain, and skin/hair changes. The patient recalls being told that he has lumps in his thyroid. He has no family history of thyroid disease, is a nonsmoker, and takes only a daily aspirin. On today’s examination, a 2-cm nodule in the left lobe of the thyroid is palpated, but the rest of the thyroid does not appear enlarged or tender to palpation. The patient’s reflexes are within normal limits. There is no lid lag or signs of exophthalmos. Laboratory results obtained during this presentation reveal the following: TSH, 0.05 µIU/mL; free thyroxine (T4), 1.56 ng/dL (normal, 0.8-1.8 ng/dL); total T4, 9.3 µg/dL (normal, 4.5-12 µg/dL); and total T3, 103 ng/dL (normal, 80- 181 ng/dL). What is this patient’s most likely diagnosis? .............................. A. Euthyroid sick syndrome B. Subacute thyroiditis C. Subclinical hyperthyroidism (SCH) from Graves’ disease D. SCH from a toxic adenoma
Answer: D. SCH from a toxic adenoma. SCH is defined as suppressed serum TSH (below the lower limit of the reference range) in the setting of normal serum free T3 and T4. In the United States, SCH has a prevalence between 0.7% and 15.4%, depending on the regional dietary iodine intake and age of the population. Given the presence of a nodule in the gland, a likely cause of SCH in this patient is a toxic uni- or multinodular goiter. Although Graves’ disease, subacute thyroiditis, and drug-induced thyroiditis are potential causes of SCH, they are not likely the cause of this patient’s hyperthyroidism. Graves’ disease is less likely given the presence of a nodule; subacute thyroiditis is unlikely because the timing of disease onset is not consistent with thyroiditis and the thyroid was not tender on physical examination; and drug-induced thyroiditis is unlikely given that the patient only takes aspirin, which is not associated with thyroiditis. SCH must be carefully differentiated from euthyroid sick syndrome by repeated monitoring of serum TSH levels over time. Most patients with SCH present without symptoms.
200
A 40-year-old woman has noted enlargement of her anterior neck region over the past 8 months. On physical examination her vital signs include T 36.8 C, P 64/minute, RR 15/minute, and BP 155/105 mm Hg. There is diffuse, symmetrical thyroid enlargement without tenderness. A chest radiograph is normal. Fine needle aspiration of the thyroid yields cells consistent with a neoplasm. Laboratory studies show that she is euthyroid, but her serum ionized calcium is elevated. She is taken to surgery and frozen sections of several thyroid masses show a malignant neoplasm composed of polygonal cells in nests. A thyroidectomy is performed. Immunostaining for calcitonin of the permanent sections is positive, and the neoplasm has an amyloid stroma with Congo red staining. Which of the following neoplasms is she most likely to have? .............................. A. Anaplastic carcinoma B. Medullary carcinoma C. Papillary thyroid carcinoma D. Metastatic renal cell carcinoma E. Parathyroid carcinoma F. Follicular carcinoma
Answer: B - She has MEN IIa, with medullary thyroid carcinomas (often multiple when familial), parathyroid hyperplasia, and pheochromocytoma. Anaplastic thyroid carcinoma is a rare, aggressive neoplasm. This would not explain her hypercalcemia or hypertension. Papillary carcinomas do not have amyloid stroma nor calcitonin positivity and do not lead to hypercalcemia or hypertension. Metastases should not be operated. These are not histologic features of renal cell (clear cell) carcinomas, though some renal cell carcinomas are accompanied by hypertension. Hypercalcemia and hypertension could complicate parathyroid carcinomas, but these are not histologic features of such a lesion. Follicular carcinomas are not calcitonin positive and are not associated with MEN.
200
Hemoglobin A1c assays are INACCURATE in patients with .............................. A. Secondary hypertension B. AIDS C. Cor pulmonale D. Sickle cell disease E. Polycythemia vera
What is D. Sickle cell disease The glycosylated hemoglobin assay is rendered inaccurate by conditions affecting red blood cell survival, such as sickle cell disease or the presence of hemoglobin C.
300
Which of these insulins is best for a patient who has gastroparesis at mealtime? .............................. A. Humalog B. Novolog C. Regular D. Apidra
The Answer is C. Regular Insulin. In patients with gastroparesis and delayed absorption, it is important to tailor the insulin response as closely as possible to their gastric motility and absorption. Therefore in this situation, regular insulin would be a good choice as it has a slower time of onset as well as peak efficacy versus that of the fast acting insulins.
300
Routine blood tests frequently reveal elevated calcium levels. When this elevation is associated with elevated parathyroid hormone levels, which one of the following is an indication for parathyroid surgery? .............................. A. Age >50 B. Kidney stones C. Serum calcium 0.5 mg/dL above the upper limit of normal D. Concurrent hyperthyroidism E. Increased bone density
What is B. Kidney stones Indications for parathyroid surgery include kidney stones, age less than 50, a serum calcium level greater than 1 mg/dL above the upper limit of normal, and reduced bone density. Hyperthyroidism is not a factor in deciding to perform parathyroid surgery.
300
A healthy 72-year-old female comes to your office for a follow-up visit. She has hypertension which is well controlled with an ACE inhibitor. Routine laboratory tests are normal except for a serum calcium level of 10.8 mg/dL (N 8.5–10.5). A repeat calcium level is 11.1 mg/dL. Which one of the following would be most appropriate at this point? (check one) .............................. A. Radiographs of the hands B. An osteocalcin level C. An intact parathyroid hormone (PTH) level D. A 25-OH Vitamin D level
What is C. An intact parathyroid hormone (PTH) level In primary hyperparathyroidism, hypercalcemia is the result of excessive PTH secretion by one or more abnormal, enlarged parathyroid glands. Laboratory findings in most patients with primary hyperparathyroidism reflect the mild clinical presentation of the disorder. The serum calcium level is often 1 mg/dL or more above the upper limits of normal. Bone radiographs may show the classic changes of subperiosteal bone resorption in the occasional patient with hyperparathyroidism, but in most cases they are normal or may show osteopenia. Osteocalcin is an osteoblast-specific protein. It is a marker of increased skeletal turnover, and it is usually not indicated clinically. The development of highly sensitive and specific assays for intact, largely active PTH has simplified the assessment of parathyroid activity. Bone densitometry is a test to determine the degree of osteoporosis.
300
Patient a 57 year old caucasian female who comes into your office for a routine follow up visit. On physical exam, a nodule is palpated over the thyroid. You order thyroid function tests that show normal TSH, FT3, and FT4. What is the best next step? .............................. A. Order RAIU B. Thyroid ultrasound C. Refer to surgery D. Start Iodine
Answer B. Thyroid Ultrasound
300
A frail 83-year-old male with a 10-year history of diabetes mellitus is admitted to a nursing home. His blood glucose level, which he rarely checks, is typically over 200 mg/dL. His serum creatinine level is 1.9 mg/dL. He also has had several episodes of heart failure. His current medications include glipizide (Glucotrol), lisinopril (Prinivil, Zestril), and furosemide (Lasix). Which one of the following would be most appropriate to add to this patients regimen to treat his diabetes mellitus? .............................. A. The American Diabetes Association 1800-calorie/day diet B. Metformin (Glucophage) C. Pioglitazone (Actos) D. Exenatide (Byetta) E. Insulin glargine (Lantus)
What is E. Insulin glargine (Lantus)
400
A 67-year-old female presents with progressive weakness, dry skin, lethargy, slow speech, and eyelid edema. Of the following medications currently taken by this patient, which one is most likely to be causing her symptoms? .............................. A. Donepezil (Aricept) B. Lithium C. Lisinopril (Prinivil, Zestril) D. Alendronate (Fosamax) E. Glyburide (DiaBeta, Micronase)
What is B. Lithium
400
Which one of the following medications should be discontinued in a patient with diabetic gastroparesis? (check one) .............................. A. Exenatide (Byetta) B. Benazepril (Lotensin) C. Metformin (Glucophage) D. Hydrochlorothiazide E. Prochlorperazine maleate
What is A. Exenatide (Byetta)
400
The patient is a 45 year old male who comes into your office with known history type II diabetes diagnoses 2 years ago. He is on metformin and Byetta, but has not achieved good glycemic control. Upon discussion, you discover that he is not taking his Byetta daily because he forgets. He however, does not mind the injections. What would be the next best course of action? .............................. A. Start the patient on Humalog B. Start the patient on Lantus C. Convince the patient that he should be more compliant D. Discontinue Byetta and Start Bydureon
The answer is D. Discontinue Byetta and start Bydureon. Byetta and Bydureon are both GLP-1 agonists (exanitide) that enhance insulin secretion in response to glucose. Bydureon, however, is a new formulation that requires only once a week injection and would be a better choice for this patient since he does not mind injections.
400
A patient is admitted to you service in the hospital for diarrhea and vomiting. She has a significant history of pituitary macroadenoma s/p resection 5 years ago. She takes 100mcg of synthroid daily. You check a TSH and it is undetectable. What is your next best course of action? .............................. A. Increase Synthroid Dose B. Decrease Synthroid Dose C. Keep Current Dose of Synthroid D. None of the Above
Answer is D. None of the above. This patient has panhypopituitarism secondary to pituitary resection. It is necessary to first check a FT4 level to determine how her synthroid should be adjusted.
400
A 27 year old female comes into your office with a known hx of anxiety and palpitations. She is currently sexually active and employs the use of barrier contraceptives and Nuva ring. She is also taking fluoxetine for anxiety and sumitriptan for migraines. You check a thyroid which shows a normal TSH. Her Total T4 and T3 are slightly elevated however. What is her most likely diagnosis? .............................. A. Subclinical hyperthyroidism B. Lab Error C. Secondary Medications D. Overt Hyperthryoidism
The answer is C. Secondary to Medications. The patient is on Nuvaring which releases a low dose of progestin and estrogen. The estrogen component increases the binding component of Thryoid hormones and may increase total Thyroid levels. Suspicion of hyperthroidism or any other pathology should be based on clinical judgement and free thyroid levels.
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