Updated: 10/10/2016

Hyperparathyroidism

Topic
Review Topic
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0
Questions
3
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Evidence
6
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Cases
1
https://upload.orthobullets.com/topic/9089/images/subperiosteal_resorption.jpg
Introduction
  • Increased parathyroid hormone (PTH) production that may be of primary, secondary or tertiary causes
  • Epidemiology 
    • incidence
      • occurs in 0.1% of the population
      • 90% result form a single adenoma
      • remaining 10% from parathyroid hyperplasia
    • demographics
      • more common in women
      • hyperparathyroidism and maligncacy make up the majority of patients with hypercalcemia
  • Pathophysiology
    • PTH indirectly stimulates osteoclasts by binding to its receptor on osteoblasts, inducing RANK-L and M-CSF synthesis 
    • Excessive PTH leads to over-stimulation of bone resorption
      • cortical bone affected more than cancellous
  • Associated conditions
    • Brown tumor
      • resembles a giant cell tumor of bone relating to focal demineralization of bone in the setting of hyperparathyroidism.
Classification
  • Primary
    • typically the result of hypersecretion of PTH by a parathyroid adenoma/hyperplasia
    • may result in osteitis fibrosa cystica
      • breakdown of bone, predominently subperiosteal bone
      • commonly involves the jaw
  • Secondary
    • secondary parathyroid hyperplasia as compensation from hypocalcemia or hyperphosphatemia
      • ↓ gut Ca2+ absorption
      • ↑ phosphorous
    • associated conditions
      • chronic renal disease
        • renal disease causes hypovitaminosis D
          • leads to ↓ Ca2+ absorption
      • renal osteodystrophy
        • bone leisons due to secondary hyperparathyroidism 
  • Tertiary
    • parathyroid glands become dysregulated after secondary hyperparathyroidism
      • secrete PTH regardless of Ca2+ level
      Serum Ca Serum Phos Serum PTH
    Primary 
    Secondary
    normal or ↓
    Tertiary
Presentation
  • Symptoms
    • often asymptomatic
    • weakness
    • kidney stones ("stones")
    • bone pain ("bones")
    • constipations ("groans")
    • uncommon cause of secondary hypertension
Evaluation
  • Serology
    • primary
      • hypercalcemia
      • ↑ PTH
    • secondary
      • hypocalcemia/normocalcemia 
      • ↑ PTH
    • malignancy
      • ↓ PTH
    • ↑ alkaline phosphatase
    • normal anion gap metabolic acidosis
      • ↓ renal reclamation of bicarbonate
  • Urinalysis
    • primary
      • hypercalciuria (renal stones)
      • ↑ cAMP
  • Radiograph
    • cystic bone spaces ("salt and pepper")
      • often in the skull
    • loss of phalange bone mass
      • ↑ concavity (see key image of this topic)
  • EKG
    • shortened QT
Treatment
  • Acute hypercalcemia
    • IV fluids
    • Loop diuretics
  • Symptomatic hypercalcemia is treated surgically
    • treat with parathyroidectoy
    • complications include post-op hypocalcemia
    • manifests as numbness, tingling, and muscle cramps
    • should be treated with IV calcium gluconate 
Complications
  • Peptic ulcer disease
    • ↑ gastrin production stimulated by ↑ Ca2+
  • Acute pancreatitis
    • ↑ lipase activity stimulated by ↑ Ca2+
  • CNS dysfunction
    • anxiety, confusion, coma
    • result of metastatic calcification of the brain
  • Osteoporsis
    • Bone loss occurs as result of bone resorption due to excess PTH
 

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Questions (3)

(OBQ13.185) A 25-year-old female presents to the emergency room within increasing left shoulder pain after walking into a door 5 months ago. She previously sustained a femoral fracture 2 years ago after tripping on a rug. Relevant skeletal survey radiographs and tissue biopsy results are shown in Figures A through D. Laboratory investigations show normal glomerular filtration rate and creatinine clearance. Dual energy x-ray absorptiometry (DEXA) scan shows T-score of -1.4 and -1.2 at the hip and lumbar spine, respectively. Which of the following laboratory values in Figure E most likely reflects this patient's condition? Review Topic

QID: 4820
FIGURES:
1

A

46%

(1697/3650)

2

B

24%

(893/3650)

3

C

14%

(494/3650)

4

D

8%

(307/3650)

5

E

6%

(206/3650)

ML 4

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

(OBQ11.57) A 35-year-old female complains of 1 month of right hip pain during ambulation. Her medical history includes end-stage renal disease for which she is on hemodialysis three times per week. A radiograph of the right hip, spine, and skull are shown in Figures A-C. Figure D shows a histology microphotograph of a biopsy specimen. All of the following laboratory findings are associated with this condition EXCEPT? Review Topic

QID: 3480
FIGURES:
1

Hypophosphatemia

49%

(1081/2217)

2

Hypocalcemia

20%

(437/2217)

3

Decreased 1,25-(OH)2-vitamin D3

9%

(197/2217)

4

Increased alkaline phosphatase

14%

(306/2217)

5

Increased BUN

8%

(185/2217)

ML 4

Select Answer to see Preferred Response

PREFERRED RESPONSE 1
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ARTICLES (6)
CASES (1)
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