Question

Radiographic findings in hyperparathyroidism.

Hint:

In hyperparathyroidism, look for osteitis fibrosa cystica and subperiosteal resorption on X-rays, particularly in the hands, feet, and jaw.

Answer 1

Step 1: Understanding Hyperparathyroidism.
Hyperparathyroidism is a condition characterized by excessive secretion of parathyroid hormone (PTH), which leads to elevated blood calcium levels. The condition can be primary (due to a parathyroid adenoma or hyperplasia), secondary (due to chronic kidney disease), or tertiary (resulting from long-standing secondary hyperparathyroidism). Radiographic findings in hyperparathyroidism are mainly related to bone changes due to the effects of elevated PTH on bone metabolism.

Step 2: Radiographic Findings in Hyperparathyroidism.

1. Osteitis Fibrosa Cystica (OFC):
- Classic finding: Osteitis fibrosa cystica is a hallmark of long-standing hyperparathyroidism. It is characterized by subperiosteal bone resorption, particularly at the phalanges (fingers and toes), and may present with "salt and pepper" appearance in the skull.
- Radiographic Appearance: Bone cysts, cortical thinning, and bone resorption are visible on X-rays, particularly in the hands, feet, and jaw.

2. Brown Tumors of Bone:
- Findings: Brown tumors are osteolytic lesions caused by the accumulation of hemorrhagic and fibrous tissue in the bone due to hyperparathyroidism. They appear as well-defined, lytic lesions on radiographs, often in the pelvis, femur, and jaw.
- Appearance: They have a characteristic "soap bubble" appearance due to the fibrous tissue, and may be mistaken for other bone lesions like giant cell tumors.

3. Renal Involvement:
- Nephrocalcinosis: Hyperparathyroidism can lead to calcium deposition in the kidneys, seen as radiopaque areas on abdominal X-rays, particularly in the renal cortex. This is known as nephrocalcinosis.
- Kidney Stones: Patients with hyperparathyroidism may also develop kidney stones, which appear as radiopaque areas on plain abdominal X-rays or on CT scans.

4. Subperiosteal Bone Resorption:
- The most characteristic feature of hyperparathyroidism is subperiosteal bone resorption, which often affects the distal phalanges and can be seen as resorption of the bone cortex, leaving behind a "cupped" appearance at the bone margins.

Step 3: Conclusion.
Radiographic findings in hyperparathyroidism include osteitis fibrosa cystica, brown tumors, subperiosteal resorption, and nephrocalcinosis. These findings are useful for diagnosing and assessing the effects of chronic hyperparathyroidism on the skeletal system and kidneys.