A 35-year-old man comes to the office due to fatigue, palpitations, and weight loss. He has lost more than 4.5 kg (10 lb) in the last few months. He has been under a lot of stress at work, and his sleep is poor. The patient also has bilateral eye irritation, excessive tearing, and redness. He has no fever, shortness of breath, bone pain, or abdominal symptoms. He takes lisinopril for hypertension.
The patient tested negative for HIV 5 months ago after a new sexual encounter. He takes no over-the-counter medications. He smoked cigarettes for a year when he was in his early 20s. The patient drinks a glass of red wine every Friday. He works as a manager in a department store. His father died of prostate cancer at age 65, and his mother had a lumpectomy for breast cancer.
Temperature is 37.2 C (99 F), blood pressure is 150/80 mm Hg, pulse is 104/min and regular, and respirations are 18/min. The patient has no enlarged lymph nodes, and his spleen is not palpable. There is swelling of soft tissues around his eyes but no proptosis. The remainder of the physical examination is unremarkable.
Laboratory results are as follows:

Repeat serum calcium is 10.8 mg/dL. Serum parathyroid hormone is 7 pg/mL, 1,25-dihydroxyvitamin D is 19 pg/mL (25-65 pg/mL), and 25-hydroxyvitamin D is 30 ng/mL (15-80 ng/mL).
Which of the following is most likely to provide the etiology for this patient's hypercalcemia?

Question

A 35-year-old man comes to the office due to fatigue, palpitations, and weight loss.  He has lost more than 4.5 kg (10 lb) in the last few months.  He has been under a lot of stress at work, and his sleep is poor.  The patient also has bilateral eye irritation, excessive tearing, and redness.  He has no fever, shortness of breath, bone pain, or abdominal symptoms.  He takes lisinopril for hypertension.
The patient tested negative for HIV 5 months ago after a new sexual encounter.  He takes no over-the-counter medications.  He smoked cigarettes for a year when he was in his early 20s.  The patient drinks a glass of red wine every Friday.  He works as a manager in a department store.  His father died of prostate cancer at age 65, and his mother had a lumpectomy for breast cancer.
Temperature is 37.2 C (99 F), blood pressure is 150/80 mm Hg, pulse is 104/min and regular, and respirations are 18/min.  The patient has no enlarged lymph nodes, and his spleen is not palpable.  There is swelling of soft tissues around his eyes but no proptosis.  The remainder of the physical examination is unremarkable.
Laboratory results are as follows:

Repeat serum calcium is 10.8 mg/dL.  Serum parathyroid hormone is 7 pg/mL, 1,25-dihydroxyvitamin D is 19 pg/mL (25-65 pg/mL), and 25-hydroxyvitamin D is 30 ng/mL (15-80 ng/mL).
Which of the following is most likely to provide the etiology for this patient's hypercalcemia?

Quizplus · Accepted Answer

11ec193a_97ad_0977_853d_c7e41ad63e0c_MD0002_00 This patient's presentation is consistent with thyrotoxicosis-associated hypercalcemia, likely due to Graves' disease. Clinical features suggesting thyrotoxicosis include fatigue, palpitations, weight loss, increased heart rate, and systolic hypertension. In addition, this patient's eye symptoms and orbital soft tissue inflammation suggest associated Graves' ophthalmopathy. Thyroid hormone acts on osteoclasts to increase bone turnover. This leads to decreased bone density and osteoporosis, with an associated increase in fracture risk. Laboratory testing typically shows hypercalciuria and sometimes mild hypercalcemia. Parathyroid hormone levels are suppressed, leading to renal calcium wasting and a negative calcium balance. 1,25-hydroxyvitamin D levels will be low due to increased catabolism and decreased parathyroid hormone-mediated renal conversion from 25-hydroxyvitamin D. Treatment of the hyperthyroidism will correct the metabolic abnormalities but does not always restore the bone density that has been lost. (Choice A) A CT scan of the chest and neck can diagnose malignancies (eg, lymphoma) that may be associated with hypercalcemia due to increased conversion of 25-hydroxyvitamin D to 1,25-hydroxyvitamin D in the malignant cells. This patient has low 1,25-hydroxyvitamin D and no physical signs of malignancy. (Choice B) Parathyroid hormone-related peptide secretion by malignancies (eg, squamous cell lung cancer) typically causes moderate to severe hypercalcemia and is usually seen in patients with advanced malignancy. This patient's mild hypercalcemia and hyperthyroid features are more consistent with thyrotoxicosis. (Choice C) Acute HIV can have a variety of clinical presentations, including a viral-like syndrome with fever, upper respiratory symptoms, oral ulcers, skin rash, gastrointestinal symptoms, generalized lymphadenopathy, and aseptic meningitis. However, acute HIV does not usually cause hypercalcemia. (Choice D) Multiple myeloma causes hypercalcemia due to increased bone resorption, usually associated with anemia, renal dysfunction, bone pain, and a monoclonal protein on serum protein electrophoresis. This patient's young age, normal renal function, and blood counts make this less likely. Educational objective: Thyrotoxicosis is a cause of parathyroid hormone-independent hypercalcemia. It can lead to a negative calcium balance, decreased bone density, and increased risk of fracture. __________ References: Hypercalcemia in hyperthyroidism: patterns of serum calcium, parathyroid hormone, and 1, 25-dihydroxyvitamin D3 levels during management of thyrotoxicosis. (http://www.ncbi.nlm.nih.gov/pubmed/14715479)

A 35-Year-Old Man Comes to the Office Due to Fatigue