In this case, a 67-year old man with prostate
cancer since the age of 63 comes to see you.
His only symptom is new-onset upper back pain.
He takes no medication.
On physical examination, his vital signs are normal.
His spine is tender to palpation
over the thoracic area.
Lab studies show serum calcium level of 9.6
mg/dL, a serum creatinine level of 1.0 mg/dL
A serum Alk Phos of 240 and a PSA of less than 4 ng/mL.
Whole body radionucleide bone scan
shows focal increase uptake at T7.
There are no other abnormalities.
The spine x-ray shows coarsening of trabeculae and
expansion of the body of T7 without cortical disruption.
What is the most likely diagnosis?
In this scenario, we have an elderly
patient with a history of prostate cancer
presenting with back pain and
point tenderness over the spine.
In ruling out bone metastases, he has an incidental finding
of coarsened trubeculae in a single vertebra on x-ray
in conjunction with an increase
in his alkaline phosphatase.
This patient most likely has a
diagnosis of Paget's disease.
An elevated alkaline phosphatase and finding on
radiographs of coarsening of bone trubeculae
are most consistent with
Paget's disease of the bone.
Alkaline phosphatase level reflects the
metabolic activity of Paget's disease,
at diagnosis, and it's used in follow up to
evaluate whether they are responding to treatment.
Although Paget's disease of bone may
present with localized symptoms,
it is most commonly diagnosed
in asymptomatic older patients
presenting with elevated levels of alkaline
phosphatase and incidental radiographic findings.
Paget's disease is a focal disorder of bone remodelling.
Accelerates the rates of bone turnover results and
there is disruption of the normal architecture of bone.
Enlarged skull, bowing of the tibia or femur
are classic deformities that may be seen.
Most patients are asymptomatic.
It should be suspected clinically when there
is isolated compression of a cranial nerve,
high-output heart failure or angioid
streaks are seen on the retina.
Fortunately all of these presentations
are fairly rare in Paget's disease
but in the advanced form of the disease,
elevated alkaline phophatase in conjunctin
with these findings help clinch the diagnosis.
These patients are usually treated
in the long term with bisphosphonates.
In this x-ray, the changes cause by Paget's disease
result in osteolytic changes and osteosclerotic changes.
The lytic changes are represented by the white arrows
and the sclerotic changes by the white arrowheads.
As you can see, there is an overall impression
of an increased density in the bone
on the left acetabulum, the left half
of the ilium and the pubic bone.
This is classic radiographic feature
of Paget's disease of bone.