Yes, refer this patient for parathyroid surgery
This patient has primary hyperparathyroidism (PHPT) with renal stones, which is a clear indication for surgical referral according to the most recent expert consensus guidelines. 1
Diagnostic Confirmation
Your patient's biochemical profile confirms PHPT:
- Mild hypercalcemia (total calcium 10.6 mg/dL, assuming normal range ~8.5-10.2 mg/dL)
- Elevated ionized calcium (5.9 mg/dL, normal ~4.6-5.3 mg/dL)
- Non-suppressed PTH (31 pg/mL) - this is the key finding. In hypercalcemia from other causes, PTH should be suppressed (<20 pg/mL). A "normal" or elevated PTH in the setting of hypercalcemia is inappropriate and diagnostic of PHPT 2
Surgical Indication
The 2025 French Expert Consensus Statement explicitly recommends surgery when PHPT patients present with "proven renal colic or urinary excretory tract lithiasis or nephrocalcinosis on X-ray, ultrasound or CT scan" 1. Your patient meets this criterion with documented renal stones.
The guideline states: "Excision of the lesion is recommended as soon as there are clinical consequences" 1. Renal stones represent a clinical consequence and target organ involvement, making this symptomatic PHPT rather than asymptomatic disease.
Additional Surgical Criteria to Verify
Before referral, ensure you've assessed these other potential surgical indications 1:
- Bone involvement: Check bone densitometry for T-score <-2.5 SD or history of low-energy fractures
- Renal function: Verify eGFR (surgery indicated if <60 mL/min/1.73 m²)
- 24-hour urinary calcium: Measure if not already done (surgery indicated if >250 mg/day in women or >300 mg/day in men, though recent evidence questions this threshold's utility 3)
- Severity of hypercalcemia: Your calcium is only mildly elevated (~0.4 mg/dL above normal), but the presence of stones supersedes this consideration
Expected Surgical Benefit
Surgery prevents new stone formation in PHPT patients with nephrolithiasis, though the benefit takes time to manifest. Studies show operated patients eventually reach the same low risk of stone recurrence as the general population after approximately 10 years 4. The biochemical cure rate for PHPT surgery is high with low complication rates when performed by experienced endocrine surgeons 4.
Pre-Surgical Workup
Once you've decided on surgery 1:
- Correct vitamin D deficiency if present before final PTH interpretation
- Renal imaging: Preferably low-dose CT urography (superior to ultrasound) to fully characterize stone burden and detect nephrocalcinosis
- Localization imaging: Parathyroid ultrasound PLUS either dual-isotope scintigraphy (¹²³I/⁹⁹mTc-Sestamibi) or ¹⁸F-Choline PET-CT
- Refer to an experienced endocrine surgeon, not a general surgeon
Common Pitfall
Do not be misled by the "normal-range" PTH of 31 pg/mL. In the context of hypercalcemia, any PTH that is not suppressed (<20 pg/mL) is pathologically elevated and indicates PHPT 2. This is "inappropriate PTH secretion" and confirms autonomous parathyroid function.