Osteopetrosis, or Albers-Schönberg disease, is an uncommon hereditary disorder that results from defective osteoclasts. Bones become sclerotic and thick, but their abnormal structure results in them being both weak and brittle.
There are two separate subtypes of osteopetrosis:
Presentation in the majority of cases is with fracture because of the weakened bones. They are often transverse fractures with multiple areas of callus formation and normal healing.
Additionally, there is crowding of the marrow, so bone marrow function is affected resulting in myelophthisic anaemia and extramedullary haematopoiesis with splenomegaly. This may terminate in acute leukaemia.
Both forms are congenital abnormalities with localised chromosomal defects. These result in defective osteoclasts and overgrowth of bone. The bones become thick and sclerotic, but their increased size does not improve their strength. Instead, their disordered architecture results in weak and brittle bones. The osteoclasts lack carbonic anhydrase which may play a role in the disease.
The features are dependant on the subtype of osteopetrosis and are detailed in the individual articles:
Treatment and prognosis
Treatment is with bone marrow transplant and resultant normalisation of bone production. Prognosis for the AD adult subtype is good with a normal life expectancy. However, the AR infantile subtype can result in stillbirth or death in infancy - few patients live past middle-age.
General imaging differential considerations include:
- heavy metal poisoning (e.g. lead)
- hypervitaminosis D
- fibrous dysplasia of skull or face
Metabolic bone disease
- bone mineralisation
- pituitary gland-related
- thyroid gland-related
- osteosclerosis (differential diagnosis | mnemonic)
- 1. Kolawole TM, Hawass ND, Patel PJ et-al. Osteopetrosis: some unusual radiological features with a short review. Eur J Radiol. 1988;8 (2): 89-95. Pubmed citation
- 2. Curé JK, Key LL, Goltra DD et-al. Cranial MR imaging of osteopetrosis. AJNR Am J Neuroradiol. 2000;21 (6): 1110-5. AJNR Am J Neuroradiol (full text) - Pubmed citation