Hyperparathyroidism Secondary to Renal Osteodystrophy
Sarah E Maier, MD candidate
Attending???
Presentation
A 50-year-old man with end-stage renal disease and hypertension presented
after a hypotensive episode and temperature spike following dialysis.
Imaging Findings
PA chest radiograph
Lateral chest radiograph
PA and lateral chest films
demonstrate radiographic signs of chronic
secondary hyperparathyroidism. This
included the "rugger-jersey" spine and
subligamentous bone resorption of the distal
clavicle.
Differential Diagnosis
Radiographically, there are five characteristic signs of hyperparathyroidism
- subperiosteal resorption
- osteopenia
- brown tumors
- chondrocalcinosis
- osteosclerosis
Subperiosteal resorption of bone on the
radial aspects of the middle phalanges of the
fingers is the earliest feature of
hyperparathyroidism and is virtually
diagnostic. Later in the disease, medial
margins of the femoral neck and the inner
aspect of the proximal tibia demonstrate
evidence subperiosteal resorption.
Subligamentous bone resorption most often
affects the inferior aspect of the distal
clavicle at which the coracoclavicular
ligament attaches. Generalized osteopenia
typically accompanies hyperparathyroidsim
which is best seen with a skull film. Brown
tumors are usually found only in
hyperparathyroidism. They contain fibrous
tissue, giant cells, osteoclasts and blood.
Radiographically they appear as lucent cyst-
like lesions most frequently occurring in
either the mandible, pelvis or femurs. Most
heal once the serum level of parathyroid
hormone is decreased.
Osteosclerosis rarely occurs in primary
hyperparathyroidism and therefore coupled
with the other radiographic finding suggest
that there is renal failure. Alternatively,
brown tumors are an infrequent finding in
secondary hyperparathyroidism.
Diagnosis
Secondary Hyperparathyroidism due to renal
osteodystrophy
Discussion
Parathyroid hormone promotes the release of
calcium into the blood from bone by
osteolysis. When there is excess amounts of
this hormone in the serum, it is categorized
as either being primary or secondary
hyperparathyroidism. In primary
hyperparathyroidism, excess amounts of
parathyroid hormone is released because of a
tumor of the parathyroid gland, usually an
adenoma. Secondary hyperparathyroidism
usually results from a dysfunctional kidney.
Vitamin D fails to be converted into its active
form because the kidney, which is
responsible for this reaction, is non-
functioning. This in turn decreases the
absorption of calcium from the gut and an
overall decrease in serum calcium. In
addition, the serum phosphate levels increase
because of lack of excretion by the kidney.
The combination of overall decreased serum
calcium and phosphate stimulates the
parathyroid gland to produce excess amounts
of parathyroid hormone stimulating
osteolysis in an effort to raise the serum
calcium. Renal osteodystrophy is a term used
to describe the combination of kidney
abnormalities coupled with
hyperparathyroidism and the associated soft
tissue and skeletal changes.
References
Juhl JH, Paul ??. Paul and Juhl's essentials
of radiologic imaging. Crummy AB, ed??.
Philadelphia: Lippincott, 1993, 237-243.
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PA chest radiograph
Lateral chest radiograph