March 2012 - Endocrinology - Quiz, Flashcards & Trivia

1. A 23-year-old woman is evaluated after having no menses for 6 months. She began menstruating at age 12 years, and menses have always been regular. The patient reports no recent weight gain, voice change, or facial hair growth; she says she may even have lost some weight recently and tends to feel warm. She is not sexually active. There is no family history of infertility or premature menopause. On physical examination, temperature is normal, blood pressure is 115/72 mm Hg, pulse rate is 66/min, respiration rate is 14/min, and BMI is 22. She has no acne, hirsutism, or galactorrhea. Her thyroid gland is slightly enlarged. Visual field testing yields normal results. Results of standard laboratory studies are normal, including thyroid-stimulating hormone and free thyroxine (T4) levels; a human chorionic gonadotropin level is negative for pregnancy. Which of the following is the most appropriate first step in evaluation?

Hysterosalpingography

Measurement of serum follicle-stimulating hormone and prolactin levels

Measurement of total serum testosterone level

Pelvic ultrasonography

The most appropriate first step in evaluating this patient is to measure serum follicle-stimulating hormone (FSH) and prolactin levels. This is because the patient presents with amenorrhea, which could be due to a hormonal imbalance. Measuring FSH levels can help determine if the patient has primary ovarian failure, while measuring prolactin levels can help identify any abnormalities in the hypothalamic-pituitary axis. This initial step will provide important information to guide further evaluation and management of the patient's condition.

Explanation

The most appropriate first step in evaluating this patient is to measure serum follicle-stimulating hormone (FSH) and prolactin levels. This is because the patient presents with amenorrhea, which could be due to a hormonal imbalance. Measuring FSH levels can help determine if the patient has primary ovarian failure, while measuring prolactin levels can help identify any abnormalities in the hypothalamic-pituitary axis. This initial step will provide important information to guide further evaluation and management of the patient's condition.

2. An obese 44-year-old woman is evaluated for persistent hyperglycemia. For the past 3 months, she has followed a strict regimen of diet and exercise in an attempt to control her hyperglycemia. Home blood glucose monitoring has shown preprandial levels between 120 and 160 mg/dL (6.7 and 8.9 mmol/L) and occasional postprandial levels exceeding 200 mg/dL (11.1 mmol/L). She has a history of hypertension and hyperlipidemia. Current medications include lisinopril, hydrochlorothiazide, and pravastatin. Vital signs and physical examination findings are normal, except for a BMI of 30. The serum creatinine level is 0.8 mg/dL (70.7 µmol/L), and the urine is negative for microalbuminuria. Which of the following is the most appropriate next step in treatment to improve her glycemic control?

Continue the diet and exercise for an additional 3 months

Begin exenatide

Begin glimepiride

Begin metformin

Begin piogltazone

The most appropriate next step in treatment to improve her glycemic control would be to begin metformin. Metformin is a first-line medication for the treatment of type 2 diabetes, particularly in overweight or obese individuals. It helps to improve insulin sensitivity and reduce hepatic glucose production, leading to better glycemic control. In this case, the patient has persistent hyperglycemia despite following a strict diet and exercise regimen, indicating the need for pharmacological intervention. Metformin is a safe and effective option in this patient, especially considering her normal renal function and lack of microalbuminuria.

Explanation

The most appropriate next step in treatment to improve her glycemic control would be to begin metformin. Metformin is a first-line medication for the treatment of type 2 diabetes, particularly in overweight or obese individuals. It helps to improve insulin sensitivity and reduce hepatic glucose production, leading to better glycemic control. In this case, the patient has persistent hyperglycemia despite following a strict diet and exercise regimen, indicating the need for pharmacological intervention. Metformin is a safe and effective option in this patient, especially considering her normal renal function and lack of microalbuminuria.

3. A 35-year-old man is evaluated for hypoglycemia. He has had type 1 diabetes mellitus for 21 years and has experienced four severe episodes of hypoglycemia in the past 2 months, two of which resulted in loss of consciousness and visits to the emergency department. These episodes have occurred both overnight and during the day. He says he can no longer feel the hypoglycemia developing. He uses a blood glucose meter eight to ten times each day, and his average blood glucose level over the past month is 95 mg/dL (5.3 mmol/L); his most current hemoglobin A1c value is 5.8%. His diabetes regimen consists of insulin glargine, 22 units at night, and insulin lispro, four to eight units before meals. Vital signs are normal. Physical examination findings are normal, with no evidence of peripheral or autonomic neuropathy. Which of the following is the most appropriate treatment?

Add metformin

Change the insulin glargine to insulin detemir

Change the insulin lispro to regular insulin

Decrease the dosage of both insulins

The patient in this scenario is experiencing recurrent episodes of severe hypoglycemia, including loss of consciousness. This suggests that his insulin doses may be too high, leading to excessive lowering of blood glucose levels. Decreasing the dosage of both insulins would help to reduce the risk of hypoglycemia. The patient's average blood glucose level and hemoglobin A1c are within target range, indicating good overall glycemic control, so adding metformin or changing the type of insulin is not necessary. Changing to regular insulin may also increase the risk of hypoglycemia. Therefore, decreasing the dosage of both insulins is the most appropriate treatment option in this case.

Explanation

The patient in this scenario is experiencing recurrent episodes of severe hypoglycemia, including loss of consciousness. This suggests that his insulin doses may be too high, leading to excessive lowering of blood glucose levels. Decreasing the dosage of both insulins would help to reduce the risk of hypoglycemia. The patient's average blood glucose level and hemoglobin A1c are within target range, indicating good overall glycemic control, so adding metformin or changing the type of insulin is not necessary. Changing to regular insulin may also increase the risk of hypoglycemia. Therefore, decreasing the dosage of both insulins is the most appropriate treatment option in this case.

4. A 55-year-old woman is evaluated for new-onset fever, productive cough, palpitations, and hyperdefecation. The patient has Graves disease treated with methimazole. She has been nonadherent to her medication regimen, not having refilled her methimazole prescription 6 weeks ago. On physical examination, temperature is 39.4 °C (102.9 °F), blood pressure is 140/85 mm Hg, pulse rate is 138/min, and respiration rate is 16/min. Examination of the neck reveals a smoothly symmetrical thyroid gland that is three time its normal size. Auscultation of the lungs reveals crackles in the left lower lobe. Cardiac examination shows tachycardia and a regular rhythm. Laboratory studies: Leukocyte count 14,300/µL (14.3 m 109/L) Alanine aminotransferase 100 U/L Aspartate aminotransferase 75 U/L Alkaline phosphatase 135 U/L Thyroid-stimulating hormone <0.1 µU/mL (0.1 mU/L) Thyroxine (T4), free 4.4 ng/dL (56.8 pmol/L) Triiodothyronine (T3), free 7.8 ng/L (12 pmol/L) A chest radiograph shows a left lower lobe infiltrate. Electrocardiography reveals sinus tachycardia. Ceftriaxone and azithromycin are begun. Which of the following is the most appropriate next step in management?

Atenolol

Propranolol, propylthiouracil, and hydrocortisone

Thyroid ablation with radioactive iodine

Thyroid scan with a radioactive iodine uptake test

The patient presents with symptoms of hyperthyroidism, including fever, palpitations, and hyperdefecation. The physical examination reveals an enlarged thyroid gland, crackles in the lungs, and tachycardia. The laboratory studies show suppressed thyroid-stimulating hormone (TSH) levels and elevated free thyroxine (T4) and triiodothyronine (T3) levels, confirming the diagnosis of thyrotoxicosis. The chest radiograph shows a left lower lobe infiltrate, indicating a possible complication of thyrotoxicosis called thyroid storm. The most appropriate next step in management is to initiate treatment with propranolol, propylthiouracil, and hydrocortisone. Propranolol will help control the symptoms of thyrotoxicosis, propylthiouracil will inhibit thyroid hormone synthesis, and hydrocortisone will block the peripheral conversion of T4 to T3.

Explanation

The patient presents with symptoms of hyperthyroidism, including fever, palpitations, and hyperdefecation. The physical examination reveals an enlarged thyroid gland, crackles in the lungs, and tachycardia. The laboratory studies show suppressed thyroid-stimulating hormone (TSH) levels and elevated free thyroxine (T4) and triiodothyronine (T3) levels, confirming the diagnosis of thyrotoxicosis. The chest radiograph shows a left lower lobe infiltrate, indicating a possible complication of thyrotoxicosis called thyroid storm. The most appropriate next step in management is to initiate treatment with propranolol, propylthiouracil, and hydrocortisone. Propranolol will help control the symptoms of thyrotoxicosis, propylthiouracil will inhibit thyroid hormone synthesis, and hydrocortisone will block the peripheral conversion of T4 to T3.

5. A 55-year-old woman is evaluated for a 6-month history of recurrent episodes of palpitations, sweating, and headaches. Medical history is otherwise unremarkable. She takes no medications. On physical examination, the patient appears anxious. Temperature is 36.9 °C (98.4 °F), blood pressure is 158/96 mm Hg, pulse rate is 88/min, respiration rate is 18/min. and BMI is 30. Findings from a general physical examination, including examination of the thyroid gland, are otherwise unremarkable. Laboratory studies: Epinephrine 320 ng/L (1747 pmol/L) Norepinephrine 1980 ng/L (11,704 pmol/L) Metanephrines 124 pg/mL (0.64 nmol/L) (normal range, 12-61 pg/mL [0.06-0.32 nmol/L]) Normetanephrines 798 pg/mL (4.47 nmol/L) (normal range, 18-112 pg/mL [0.10-0.63 nmol/L]) Thyroid-stimulating hormone 1.2 µU/mL (1.2 mU/L) Urine Norepinephrine 3215 µg/24 h (19,001 nmol/d) (normal range, 0-140 µg/24 h [0-827 nmol/d]) Metanephrines 575 µg/24 h (2915 nmol/d) (normal range, 35-460 µg/24 h [177-2332 nmol/d]) Normetanephrines 4350 µg/24 h (23,751 nmol/d) (normal range, 110-1050 µg/24 h [601-5733]) Vanillylmandelic acid 12.3 mg/24 h (62.1 µmol/d) A CT scan of the adrenal glands shows no adrenal masses. Which of the following is the most appropriate next test for this patient?

Adrenalectomy

Bilateral Adrenal Vein Sampling

Metaiodobenzylguanidine (MIBG) Scan

MRI Scan from base of skull to pelvis

The patient's symptoms, along with the elevated levels of epinephrine, norepinephrine, metanephrines, and normetanephrines in both blood and urine, suggest a diagnosis of pheochromocytoma. A MIBG scan is the most appropriate next test to localize the tumor, as it is a sensitive and specific imaging modality for detecting pheochromocytomas and other neuroendocrine tumors. Adrenalectomy would be the treatment of choice once the tumor is localized, but it is not the next step in the diagnostic workup. Bilateral adrenal vein sampling is not necessary in this case since the CT scan has already ruled out adrenal masses. An MRI scan from the base of the skull to the pelvis may not be as specific as a MIBG scan for detecting pheochromocytomas.

Explanation

The patient's symptoms, along with the elevated levels of epinephrine, norepinephrine, metanephrines, and normetanephrines in both blood and urine, suggest a diagnosis of pheochromocytoma. A MIBG scan is the most appropriate next test to localize the tumor, as it is a sensitive and specific imaging modality for detecting pheochromocytomas and other neuroendocrine tumors. Adrenalectomy would be the treatment of choice once the tumor is localized, but it is not the next step in the diagnostic workup. Bilateral adrenal vein sampling is not necessary in this case since the CT scan has already ruled out adrenal masses. An MRI scan from the base of the skull to the pelvis may not be as specific as a MIBG scan for detecting pheochromocytomas.

6. A 32-year-old woman is evaluated for a 3-month history of fatigue, nausea, poor appetite, and salt craving. She also reports a 6.0-kg (13.2-lb) weight loss over this same period. On physical examination, temperature is normal, blood pressure is 92/62 mm Hg supine and 78/58 mm Hg sitting, pulse rate is 88/min supine and 110/min sitting, respiration rate is 16/min, and BMI is 25. Her skin is tanned, and hyperpigmentation is noted in the gum line. Laboratory studies: Electrolytes Sodium 127 meq/L (127 mmol/L) Potassium 5.9 meq/L (5.9 mmol/L) Chloride 101 meq/L (101 mmol/L) Bicarbonate 24 meq/L (24 mmol/L) Adrenocorticotropic hormone 155 pg/mL (34.1 pmol/L) Cortisol (8 AM) 8 µg/dL (220.8 nmol/L) (normal range, 5-25 µg/dL [138-690 nmol/L]) Which of the following is the most appropriate next diagnostic test?

Cosyntropin stimulation test

Insulin-induced hypoglycemia test

Measurement of morning salivary cortisol level

24-Hour urine free cortisol measurement

The patient's clinical presentation, including fatigue, weight loss, hyperpigmentation, and electrolyte abnormalities, is consistent with adrenal insufficiency. The most appropriate next diagnostic test is the cosyntropin stimulation test, which measures the adrenal response to adrenocorticotropic hormone (ACTH) stimulation. In this test, synthetic ACTH (cosyntropin) is administered, and cortisol levels are measured before and after to assess adrenal function. A blunted cortisol response would confirm the diagnosis of adrenal insufficiency. The other options, such as insulin-induced hypoglycemia test, measurement of morning salivary cortisol level, and 24-hour urine free cortisol measurement, are not as specific or sensitive for diagnosing adrenal insufficiency.

Explanation

The patient's clinical presentation, including fatigue, weight loss, hyperpigmentation, and electrolyte abnormalities, is consistent with adrenal insufficiency. The most appropriate next diagnostic test is the cosyntropin stimulation test, which measures the adrenal response to adrenocorticotropic hormone (ACTH) stimulation. In this test, synthetic ACTH (cosyntropin) is administered, and cortisol levels are measured before and after to assess adrenal function. A blunted cortisol response would confirm the diagnosis of adrenal insufficiency. The other options, such as insulin-induced hypoglycemia test, measurement of morning salivary cortisol level, and 24-hour urine free cortisol measurement, are not as specific or sensitive for diagnosing adrenal insufficiency.

7. A 55-year-old man is evaluated for a 1-year history of weight gain, insomnia, fatigue, and diminished libido. The patient has an 18-month history of polymyalgia rheumatica treated with prednisone, with dosages ranging from 5 to 10 mg/d. Family history is noncontributory. He takes no other medications. On physical examination, temperature is 36.9 °C (98.4 °F), blood pressure is 140/86 mm Hg, pulse rate is 68/min, respiration rate is 18/min, and BMI is 30. The patient has a rounded, plethoric face. Bilateral gynecomastia is noted. The testes are soft in consistency but normal in size. Laboratory studies: Adrenocorticotropic hormone 4 pg/mL (0.88 pmol/L) Cortisol (AM) 0.8 µg/dL (22.1 nmol/L) (normal range, 5-25 µg/dL [138-690 nmol/L]) Dehydroepiandrosterone sulfate 0.08 µg/mL (0.22 µmol/L) Follicle-stimulating hormone 1.1 mU/mL (1.1 U/L) Luteinizing hormone 0.5 mU/mL (0.5 U/L) Prolactin 8.0 ng/mL (8.0 µg/L) Testosterone 127 ng/dL (4.4 nmol/L) Thyroid-stimulating hormone 1.5 µU/mL (1.5 mU/L) Thyroxine (T4), free 1.9 ng/dL (24.5 pmol/L) Which of the following is the most likely cause of this patient's hypogonadism?

Klinefelter syndrome

Pituitary microadenoma

Prednisone therapy

Primary testicular failure

The most likely cause of this patient's hypogonadism is prednisone therapy. Prednisone is a corticosteroid medication that can suppress the production of adrenal hormones, including cortisol. Prolonged use of prednisone can lead to adrenal insufficiency, which can result in low levels of testosterone and other sex hormones. The patient's low cortisol level and symptoms of weight gain, fatigue, and diminished libido are consistent with adrenal insufficiency caused by prednisone therapy. The other options, Klinefelter syndrome, pituitary microadenoma, and primary testicular failure, are less likely given the patient's history and laboratory findings.

Explanation

The most likely cause of this patient's hypogonadism is prednisone therapy. Prednisone is a corticosteroid medication that can suppress the production of adrenal hormones, including cortisol. Prolonged use of prednisone can lead to adrenal insufficiency, which can result in low levels of testosterone and other sex hormones. The patient's low cortisol level and symptoms of weight gain, fatigue, and diminished libido are consistent with adrenal insufficiency caused by prednisone therapy. The other options, Klinefelter syndrome, pituitary microadenoma, and primary testicular failure, are less likely given the patient's history and laboratory findings.

8. A 58-year-old man is evaluated for possible osteoporosis. He recently underwent removal of a 1.6-cm nonfunctioning pituitary adenoma and was placed on levothyroxine therapy. On physical examination, vital signs are normal. Examination of the neck reveals no palpable goiter. The testes are small and soft. Laboratory studies: Follicle-stimulating hormone <1.0 mU/mL (1.0 U/L) Luteinizing hormone <1.0 mU/mL (1.0 U/L) Testosterone 50 ng/dL (1.7 nmol/L) Thyroxine (T4), free 1.2 ng/dL (15.5 pmol/L) A dual-energy x-ray absorptiometry scan shows T-scores of –2.5 in the left hip and –2.6 in the lumbar spine. In addition to calcium and vitamin D supplementation, which of the following is the most appropriate initial treatment for this patient?

Bromocriptine

Calcitonin

Decreased dosage of levothyroxine

Testosterone

The patient's laboratory findings and physical examination are consistent with hypogonadism, which is characterized by low levels of testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Hypogonadism can lead to decreased bone density and osteoporosis. Therefore, the most appropriate initial treatment for this patient is testosterone replacement therapy, which can help improve bone density and prevent further bone loss. Calcium and vitamin D supplementation alone would not address the underlying hormonal deficiency. Bromocriptine and calcitonin are not indicated in the treatment of hypogonadism. Decreasing the dosage of levothyroxine would not address the primary issue of hypogonadism.

Explanation

The patient's laboratory findings and physical examination are consistent with hypogonadism, which is characterized by low levels of testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Hypogonadism can lead to decreased bone density and osteoporosis. Therefore, the most appropriate initial treatment for this patient is testosterone replacement therapy, which can help improve bone density and prevent further bone loss. Calcium and vitamin D supplementation alone would not address the underlying hormonal deficiency. Bromocriptine and calcitonin are not indicated in the treatment of hypogonadism. Decreasing the dosage of levothyroxine would not address the primary issue of hypogonadism.

9. A 48-year-old man comes to the office after lunch for a routine physical examination. The patient is asymptomatic but overweight. Although he has no pertinent personal medical history, he has a strong family history of diabetes mellitus. He currently takes no medications. Results of physical examination are normal. BMI is 29.2. Results of routine laboratory studies show a random plasma glucose level of 158 mg/dL (8.8 mmol/L). Which of the following terms best describes his current glycemic status?

Impaired fasting glucose

Impaired glucose tolerance

Metabolic syndrome

Type 2 diabetes mellitus

Noncategorizable

Based on the information provided, the patient has a random plasma glucose level of 158 mg/dL, which is above the normal range. However, to categorize his glycemic status, additional information is required such as fasting plasma glucose level or an oral glucose tolerance test. Without this information, his glycemic status cannot be accurately categorized, hence the term "Noncategorizable" is the best choice.

Explanation

Based on the information provided, the patient has a random plasma glucose level of 158 mg/dL, which is above the normal range. However, to categorize his glycemic status, additional information is required such as fasting plasma glucose level or an oral glucose tolerance test. Without this information, his glycemic status cannot be accurately categorized, hence the term "Noncategorizable" is the best choice.

10. A 20-year-old man is admitted to a rehabilitation hospital 2 months after sustaining head trauma in a motor vehicle accident. As he begins his rehabilitation program, he becomes increasingly fatigued as he exercises. The patient takes no medications. Physical examination reveals a pale, mentally alert young man. Blood pressure is 102/74 mm Hg, pulse rate is 60/min, respiration rate is 14/min, and BMI is 23. He has normal secondary sexual characteristics. Other examination findings are normal. Results of routine hematologic and serum chemistry studies are normal, except for a hemoglobin level of 11.7 g/dL (117 g/L). An MRI of the brain shows only changes that are compatible with his trauma with no interval change suggesting deterioration. Which of the following is the most critical test for this patient?

Measurement of morning (8AM) serum cortisol level

Measurement of serum growth hormone level

Measurement of serum luteinizing hormone level

Measurement of serum thyroid-stimulating hormone level

Measurement of morning (8AM) serum cortisol level is the most critical test for this patient because the patient is experiencing fatigue during exercise, which could be indicative of adrenal insufficiency. Adrenal insufficiency can occur as a result of head trauma, and one of the key hormones produced by the adrenal glands is cortisol. Measurement of morning serum cortisol level can help determine if the patient has adrenal insufficiency, which would require hormone replacement therapy to manage the fatigue and other symptoms.

Explanation

Measurement of morning (8AM) serum cortisol level is the most critical test for this patient because the patient is experiencing fatigue during exercise, which could be indicative of adrenal insufficiency. Adrenal insufficiency can occur as a result of head trauma, and one of the key hormones produced by the adrenal glands is cortisol. Measurement of morning serum cortisol level can help determine if the patient has adrenal insufficiency, which would require hormone replacement therapy to manage the fatigue and other symptoms.

11. A 45-year-old man is evaluated for recent onset of cold intolerance and constipation. He also reports a 2.3 kg (5.0-lb) weight gain over the past 3 months. The patient has an 8-year history of bipolar disorder successfully treated with lithium, 300 mg three times daily. Family history is notable for a mother and sister with Graves disease. His only other medication is sertraline for depression. On physical examination, blood pressure is 130/88 mm Hg, pulse rate is 58/min, respiration rate is 14/min, and BMI is 23.7. Examination of the neck shows a thyroid gland that is smooth and 1.5 times the normal size. There is no edema of the extremities. Laboratory studies: Thyroid-stimulating hormone 8.9 µU/mL (8.9 mU/L) Thyroxine (T4), free 0.9 ng/dL (11.6 pmol/L) Anti–thyroid peroxidase antibody 100 U/mL (normal range, 0-20 U/mL) Which of the following is the most appropriate next step in management?

Add levothyroxine

Add liothyronine

Check the anti-thyroglobulin antibody titer

Discontinue lithium

Give iodine supplementation

The patient's symptoms, physical examination findings, and laboratory results are consistent with hypothyroidism. The elevated TSH level and low free T4 level indicate primary hypothyroidism. The most common cause of primary hypothyroidism is autoimmune thyroiditis, which is supported by the presence of anti-thyroid peroxidase antibodies. The patient's symptoms of cold intolerance, constipation, and weight gain further support the diagnosis. The most appropriate next step in management is to add levothyroxine, a synthetic thyroid hormone, to replace the deficient thyroid hormone. This will help alleviate the patient's symptoms and restore thyroid hormone levels to normal.

Explanation

The patient's symptoms, physical examination findings, and laboratory results are consistent with hypothyroidism. The elevated TSH level and low free T4 level indicate primary hypothyroidism. The most common cause of primary hypothyroidism is autoimmune thyroiditis, which is supported by the presence of anti-thyroid peroxidase antibodies. The patient's symptoms of cold intolerance, constipation, and weight gain further support the diagnosis. The most appropriate next step in management is to add levothyroxine, a synthetic thyroid hormone, to replace the deficient thyroid hormone. This will help alleviate the patient's symptoms and restore thyroid hormone levels to normal.

12. A 44-year-old woman comes for a new patient evaluation. She reports amenorrhea, loss of libido, and fatigue that have persisted since the birth of her youngest child 7 years ago. She remembers having a difficult delivery and requiring blood transfusions when she last gave birth. She takes no medications. Physical examination reveals a pale but otherwise healthy-looking woman. Blood pressure is 92/60 mm Hg, pulse rate is 60/min, and BMI is 21.2. No galactorrhea is expressible. Laboratory studies: Sodium 133 meq/L (133 mmol/L) Follicle-stimulating hormone 1.4 mU/mL (1.4 U/L) Insulin-like growth factor 1 84 ng/mL (84 µg/L) (normal range, 101-267 ng/mL [101-267 µg/L]) Luteinizing hormone 1.8 mU/mL (1.8 U/L) Prolactin 2.3 ng/mL (2.3 µg/L) Thyroxine (T4), free 0.6 ng/dL (7.7 pmol/L) Cortisol (8 AM) 4.7 µg/dL (129.7 nmol/L) (normal range, 5-25 µg/dL [138-690 nmol/L]) Urine pregnancy test Negative Which of the following is the most appropriate initial treatment of this patient?

Estrogen and progesterone, cyclically

Free water restriction

Growth hormone

Hydrocortisone

Levothyroxine

The patient's symptoms and laboratory findings are consistent with secondary adrenal insufficiency, which can occur after severe hemorrhage and blood transfusions. The low cortisol level supports this diagnosis. Hydrocortisone is the treatment of choice for adrenal insufficiency. Estrogen and progesterone, cyclically, are not indicated as the patient is not experiencing symptoms of menopause. Free water restriction, growth hormone, and levothyroxine are not appropriate initial treatments for this patient.

Explanation

The patient's symptoms and laboratory findings are consistent with secondary adrenal insufficiency, which can occur after severe hemorrhage and blood transfusions. The low cortisol level supports this diagnosis. Hydrocortisone is the treatment of choice for adrenal insufficiency. Estrogen and progesterone, cyclically, are not indicated as the patient is not experiencing symptoms of menopause. Free water restriction, growth hormone, and levothyroxine are not appropriate initial treatments for this patient.

13. A 58-year-old man is evaluated for a 2-year history of gradually progressive fatigue and erectile dysfunction with reduced libido. A screening total testosterone measurement was 250 ng/dL (8.7 nmol/L). On physical examination, vital signs are normal, and BMI is 28. Visual fields are full to confrontation. There is no gynecomastia. Testes volume is 18 mL (normal, 18-25 mL) bilaterally. Which of the following is the most appropriate management option for this patient?

Begin a trial of sildenafil

Begin testosterone therapy

Measure his serum estradiol level

Measure his serum free testosterone level

The patient presents with symptoms of fatigue and erectile dysfunction, which are suggestive of hypogonadism. The total testosterone measurement is low, but it is important to measure the serum free testosterone level to confirm the diagnosis, as it is the biologically active form of testosterone. This will help determine if testosterone therapy is necessary. The other options, such as beginning a trial of sildenafil or measuring serum estradiol level, may be considered later depending on the results of the serum free testosterone level.

Explanation

The patient presents with symptoms of fatigue and erectile dysfunction, which are suggestive of hypogonadism. The total testosterone measurement is low, but it is important to measure the serum free testosterone level to confirm the diagnosis, as it is the biologically active form of testosterone. This will help determine if testosterone therapy is necessary. The other options, such as beginning a trial of sildenafil or measuring serum estradiol level, may be considered later depending on the results of the serum free testosterone level.

14. A 38-year-old woman is evaluated after an adrenal mass is discovered on a CT scan obtained because of abdominal pain. The patient reports a 4.0-kg (8.8-lb) weight gain over the past year but no other symptoms. She has no history of diabetes mellitus, palpitations, headaches, or sweating and no pertinent family history. She takes no medications. On physical examination, temperature is 36.9 °C (98.4 °F), blood pressure is 148/96 mm Hg, pulse rate is 88/min, respiration rate is 18/min, and BMI is 34. General physical examination findings are normal. Laboratory studies: Electrolytes Sodium 144 meq/L (144 mmol/L) Potassium 3.9 meq/L (3.9 mmol/L) Chloride 97 meq/L (97 mmol/L) Bicarbonate 29 meq/L (29 mmol/L) Adrenocorticotropic hormone 10 pg/mL (2.2 pmol/L) Aldosterone to renin activity ratio 8.7 Cortisol (8 AM) Initial measurement 19.8 µg/dL (546 nmol/L) (normal range, 5-25 µg/dL [138-690 nmol/L]) After 1 mg of dexamethasone the night before 11.1 µg/dL (306 nmol/L) (normal, <5 µg/dL [138 nmol/L]) Metanephrines Normal Urine free cortisol 95 µg/24 h (261.8 nmol/24 h) The previously obtained CT scan shows a left adrenal mass that measures 2.5 cm in its longest dimension and has an attenuation value of 12 Hounsfield units; the right adrenal gland appears small. Which of the following is the most appropriate next step in management?

Adrenal vein catheterization

Left adrenalectomy

MRI of the pituitary gland

Repeat biochemical testing in 6 months

The patient's presentation is consistent with an adrenal incidentaloma, which is an adrenal mass discovered incidentally on imaging. The patient's weight gain, hypertension, and elevated cortisol levels suggest a functional adrenal adenoma, specifically a cortisol-secreting adenoma causing Cushing syndrome. The most appropriate next step in management is surgical removal of the left adrenal gland (left adrenalectomy) to treat the functional adenoma and alleviate the symptoms. Adrenal vein catheterization is not necessary in this case because the clinical and biochemical findings strongly suggest a cortisol-secreting adenoma. MRI of the pituitary gland is not indicated as there are no symptoms or findings suggestive of a pituitary adenoma. Repeat biochemical testing in 6 months would delay treatment and does not address the underlying cause.

Explanation

The patient's presentation is consistent with an adrenal incidentaloma, which is an adrenal mass discovered incidentally on imaging. The patient's weight gain, hypertension, and elevated cortisol levels suggest a functional adrenal adenoma, specifically a cortisol-secreting adenoma causing Cushing syndrome. The most appropriate next step in management is surgical removal of the left adrenal gland (left adrenalectomy) to treat the functional adenoma and alleviate the symptoms. Adrenal vein catheterization is not necessary in this case because the clinical and biochemical findings strongly suggest a cortisol-secreting adenoma. MRI of the pituitary gland is not indicated as there are no symptoms or findings suggestive of a pituitary adenoma. Repeat biochemical testing in 6 months would delay treatment and does not address the underlying cause.

15. A 20-year-old woman is evaluated for new-onset fatigue and weight gain. She has a 5-year history of hypothyroidism for which she takes levothyroxine, 75 µg/d in the morning on an empty stomach, and has been on a stable dosage for the past 2 years; her most recent thyroid-stimulating hormone (TSH) level obtained 6 months ago was 1.0 µU/mL (1.0 mU/L). Other medications are an oral contraceptive pill, started 3 months ago and taken in the morning, and a multivitamin with iron, taken at bedtime. On physical examination, blood pressure is 110/74 mm Hg, pulse rate is 54/min, and BMI is 23.4. The thyroid gland is slightly enlarged and smooth, without nodules. Laboratory studies now show a TSH level of 15.3 µU/mL (15.3 mU/L) and a free thyroxine (T4) level of 0.9 ng/dL (11.6 pmol/L). Which of the following is the most appropriate change to this patient's treatment regimen?

Discontinue the multivitamin

Increase the levothyroxine dosage

Start desiccated thyroid hormone

Take the oral contraceptive pill at bedtime

The patient's TSH level is elevated, indicating that her hypothyroidism is not well controlled. The most appropriate change to her treatment regimen would be to increase the dosage of levothyroxine. This would help to normalize her TSH level and improve her symptoms of fatigue and weight gain. Discontinuing the multivitamin or changing the timing of the oral contraceptive pill would not address the underlying issue of inadequate thyroid hormone replacement. Starting desiccated thyroid hormone is not recommended as levothyroxine is the preferred treatment for hypothyroidism.

Explanation

The patient's TSH level is elevated, indicating that her hypothyroidism is not well controlled. The most appropriate change to her treatment regimen would be to increase the dosage of levothyroxine. This would help to normalize her TSH level and improve her symptoms of fatigue and weight gain. Discontinuing the multivitamin or changing the timing of the oral contraceptive pill would not address the underlying issue of inadequate thyroid hormone replacement. Starting desiccated thyroid hormone is not recommended as levothyroxine is the preferred treatment for hypothyroidism.

16. A 65-year-old man comes to the office for routine follow-up. He says he is feeling well. The patient has a history of a 2-cm thyroid cancer with two positive cervical lymph nodes that was treated with a total thyroidectomy and radioactive iodine therapy 1 year ago. Six months ago, results of laboratory studies showed a stimulated thyroglobulin level of less than 0.2 ng/mL (0.2 µg/L) and no thyroglobulin antibodies, and a neck ultrasound showed no evidence of any residual disease. The patient takes levothyroxine, 188 µg/d. Other medications include atenolol, 50 mg/d, for hypertension. On physical examination, vital signs are normal, and BMI is 27.9. Examination of the neck reveals a well-healed surgical scar at its base. No cervical lymphadenopathy or mass is noted. The patient has a slight bilateral upper extremity tremor. Results of laboratory studies show a thyroid-stimulating hormone level of 0.3 µU/mL (0.3 mU/L) and a free thyroxine (T4) level of 1.96 ng/dL (25.3 pmol/L). Which of the following is the most appropriate next step in management?

Decrease the dosage of levothyroxine

Increase the dosage of levothyroxine

Make no changes to the medication regimen

Measure the triiodothyronine (T3) level

The patient has a history of thyroid cancer that was treated with a total thyroidectomy and radioactive iodine therapy. Six months ago, laboratory studies showed a low stimulated thyroglobulin level and no evidence of residual disease on neck ultrasound. The patient is currently taking levothyroxine, and the results of thyroid-stimulating hormone and free thyroxine levels are within the normal range. Therefore, there is no indication to change the medication regimen at this time. Monitoring the triiodothyronine (T3) level is not necessary as the current thyroid function tests are normal.

Explanation

The patient has a history of thyroid cancer that was treated with a total thyroidectomy and radioactive iodine therapy. Six months ago, laboratory studies showed a low stimulated thyroglobulin level and no evidence of residual disease on neck ultrasound. The patient is currently taking levothyroxine, and the results of thyroid-stimulating hormone and free thyroxine levels are within the normal range. Therefore, there is no indication to change the medication regimen at this time. Monitoring the triiodothyronine (T3) level is not necessary as the current thyroid function tests are normal.