Msk Dermatology · Year 2 · from Msk Dermatology
Case 3: Primary Hyperparathyroidism with Bone Disease
Patient Presentation
Demographics: 55-year-old woman
Chief Complaint: "My doctor found high calcium on my blood work."
History of Present Illness: The patient was found to have elevated calcium (11.2 mg/dL) on routine laboratory testing. Upon questioning, she reports fatigue, constipation, and vague bone pain in her hips and back for several months. She also notes increased urinary frequency and reports passing a kidney stone 2 years ago.
Past Medical History:
- Nephrolithiasis (calcium oxalate stone)
- Depression
- GERD
Medications:
- Sertraline 50 mg daily
- Omeprazole 20 mg daily
Physical Examination
- Vital Signs: BP 145/88 mmHg, HR 72 bpm, BMI 26 kg/m2
- Neck: No palpable thyroid nodules or masses
- Musculoskeletal: Mild tenderness over lumbar spine, no focal bone tenderness
- Neurological: Normal
Workup and Results
Laboratory Studies:
| Test | Result | Reference Range |
|---|---|---|
| Calcium | 11.4 mg/dL | 8.5-10.5 mg/dL |
| Ionized Calcium | 5.9 mg/dL | 4.5-5.3 mg/dL |
| Phosphorus | 2.2 mg/dL | 2.5-4.5 mg/dL |
| PTH (intact) | 128 pg/mL | 15-65 pg/mL |
| 25-OH Vitamin D | 22 ng/mL | 30-100 ng/mL |
| Creatinine | 1.0 mg/dL | 0.6-1.2 mg/dL |
| 24-hour urine calcium | 380 mg/day | <250 mg/day |
Imaging:
- DXA: Femoral neck T-score -2.6, distal radius T-score -2.8, lumbar spine T-score -1.8
- Sestamibi scan: Focal uptake inferior to left thyroid lobe consistent with parathyroid adenoma
- Hand X-rays: Subperiosteal resorption of radial aspect of middle phalanges
Clinical Image
Hand radiograph demonstrating subperiosteal bone resorption along the radial aspects of the middle phalanges, a pathognomonic finding of hyperparathyroidism. Source: Radiopaedia, CC BY-NC-SA 3.0.
Diagnosis
Primary Hyperparathyroidism with Symptomatic Bone Disease
Diagnostic Criteria:
- Hypercalcemia (11.4 mg/dL) with inappropriately elevated PTH (128 pg/mL)
- Low phosphorus (consistent with PTH-induced phosphaturia)
- Hypercalciuria
- Radiographic evidence of bone resorption
- Sestamibi scan localizing parathyroid adenoma
Manifestations (Classic "Stones, Bones, Groans, Moans"):
- Stones: History of nephrolithiasis
- Bones: Subperiosteal resorption, osteoporosis
- Groans: Constipation
- Moans: Fatigue, depression
Treatment Plan
Surgical Management:
- Parathyroidectomy: Recommended given:
- Serum calcium >1 mg/dL above normal
- Osteoporosis (T-score <-2.5)
- History of nephrolithiasis
- Age <50 years at diagnosis consideration
- Minimally invasive parathyroidectomy with intraoperative PTH monitoring
Preoperative:
- Hydration
- Vitamin D repletion (carefully, to avoid worsening hypercalcemia)
- Repeat serum calcium and PTH day of surgery
Postoperative:
- Monitor for hungry bone syndrome (hypocalcemia)
- Calcium and vitamin D supplementation as needed
- Repeat DXA in 1-2 years
Teaching Points
- PTH effects on bone: PTH stimulates osteoblasts to increase RANKL expression, indirectly activating osteoclasts and bone resorption; continuous PTH exposure is catabolic, while intermittent exposure (as with teriparatide therapy) is anabolic
- Subperiosteal resorption: Pathognomonic radiographic finding of hyperparathyroidism, reflecting cortical bone resorption
- Skeletal pattern: Primary hyperparathyroidism preferentially affects cortical bone (distal radius) more than trabecular bone (spine)
- Surgical indications: Include symptomatic disease, calcium >1 mg/dL above normal, osteoporosis, renal stones, age <50, or reduced renal function