Increased bone mass is a sporadic finding, especially with routine bone mineral density testing. Causes are predominantly artefactual or systemic, or in rare cases genetic. A patient with unexplained high bone mass is described here, and the possible causes reviewed.
- Osteosclerosis and osteopetrosis are metabolic bone disorders that lead to trabecular and cortical bone thickening, which can be complicated by bone marrow compromise, bony overgrowth and neurological entrapment.
- Patients with these disorders may be asymptomatic or may present with generalised bone pain or fractures.
- Artefactual causes of high bone mass are common and should be excluded.
- Osteosclerosis, which may be focal or diffuse, is often secondary to metabolic, malignant or other processes but can also be due to rare hereditary disorders of osteoblastic bone formation (e.g. mutations in genes such as SOST and LRP5).
- Osteopetrosis is a generalised clinical syndrome due to defective osteoclastic bone resorption, characterised by increased fracture risk, systemic complications and distinctive radiological features.
- Unexplained high bone mass is common and is characterised by increased trabecular bone mineral density and cortical bone strength and a generally benign course.
- Treatment of osteosclerosis and osteopetrosis should target the underlying cause when possible and associated complications.
Picture credit: © Globalstock/iStockphoto. Model used for illustrative purposes only.