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Endocrinology, Diabetes and Metabolism I, Case 0020 — Calcium & Bone

Asymptomatic Paget's Disease: Treat the Alkaline Phosphatase or Watch It

A single patient with a real, imaging-confirmed diagnosis and nothing bothering her. The disagreement is whether an elevated lab value and an affected bone near a joint are reason enough to treat before anything hurts.

Abbreviations, terms, and other agents mentioned in this case ALP — alkaline phosphatase
Presentation

Hyacinth D., a 68-year-old woman, came in for an abdominal CT ordered to investigate intermittent digestive complaints that turned out to be ordinary irritable bowel symptoms. The scan's incidental view of her pelvis showed the coarsened, expanded bone architecture characteristic of Paget's disease, and the follow-up alkaline phosphatase came back at 312 U/L, roughly three times the upper limit of normal — a number that in Paget's indexes how actively the affected bone is remodeling, not how much trouble it is causing her, which is the distinction the entire visit turns on. She has no bone pain, no fracture history, still plays in a weekly pickleball league, and had never heard the term before this appointment.

What complicates an otherwise straightforward incidental finding is where it sits. Her affected segment involves the right ilium and acetabular region, close to a weight-bearing joint, which is the anatomy in which Paget's carries real potential for secondary osteoarthritis, deformity or fracture if it progresses — the kind of detail that makes "asymptomatic" feel like it might mean "not yet symptomatic" rather than "low-stakes." Against that, PRISM, the largest randomized trial addressing this question directly, compared intensive bisphosphonate therapy aimed at normalizing alkaline phosphatase with symptom-driven management and found no clinical benefit to treating in the absence of symptoms. The site-specific worry is worth stating precisely enough to notice how little supports it. PRISM randomized patients across a range of anatomic locations and was not powered to detect a difference at any one of them, so the pelvic-disease concern is not a finding the trial contradicts — it is a hypothesis the trial never tested, which is a considerably weaker thing to treat a patient on than it sounds when said aloud.

Hyacinth D. · 68 Incidental finding
Incidental finding
Coarsened, expanded bone architecture of the right ilium/acetabular region on CT
Alkaline phosphatase
312 U/L, markedly elevated
Symptoms
None — no bone pain, no functional limitation, active pickleball player
Fracture history
None
Anatomic location
Near the hip joint, weight-bearing
Calcium
9.5 mg/dL, normal

What treating a lab value before it hurts actually buys her

Endocrinologist Opening

I'd treat now with zoledronic acid rather than watch and wait. Her affected segment sits near a weight-bearing joint — treating a high-risk site before symptoms appear feels more defensible than waiting for pain or deformity that, by the time it shows up, may reflect damage already done.

Clinical Pharmacologist Response

The strongest evidence here actually argues against that intuition. PRISM, the largest randomized trial addressing exactly this question, found no clinical benefit to treating asymptomatic Paget's disease with bisphosphonates versus a symptom-driven approach. Treating a lab value and an imaging finding alone, without symptoms, isn't what the outcome data supports, even though it feels protective.

I understand the intuition about her specific site — I'm just pointing out that the best available randomized evidence found that intuition didn't translate into a measurable clinical benefit.

Rheumatologist Final

I'd push back gently on applying PRISM's overall null result uniformly, though. Its population spanned multiple anatomic sites and wasn't specifically powered to detect a site-specific signal — pelvic disease near a major joint is a real, distinguishable variable the trial's overall finding doesn't necessarily speak to directly.

I don't think that overrides the trial evidence outright, but it's a real enough gap that I'd want her own preference weighed alongside it — a conversation about the trial's limitation, not a default to either treating everyone with her imaging findings or observing everyone regardless of site.

Regimen selected
Zoledronic Acid — Deferred, Not Started
Bisphosphonate · Held pending symptom development
Withheld per PRISM's finding of no clinical benefit to treating asymptomatic Paget's disease, with her site-specific risk disclosed as a genuine, trial-unresolved consideration.
Alkaline Phosphatase Monitoring
Monitoring · Every 6–12 months
Tracks disease activity as the trigger for reconsidering treatment if it rises further or symptoms develop.
Where this was left

Agreed: observe rather than treat for now, with alkaline phosphatase and symptom checks at regular intervals, and zoledronic acid available immediately if she develops pain, a rising alkaline phosphatase trend, or any sign of joint involvement.

Not fully settled: whether her specific pelvic, near-joint location should have shifted the group toward treating despite PRISM's overall null finding — the rheumatologist's site-specific concern was disclosed to Hyacinth directly rather than resolved by the team, and she chose observation for now after hearing both sides.

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