Daily Radiology Case

Explanation

This presentation is classic for osteopetrosis, where defective osteoclast-mediated bone resorption leads to diffuse osteosclerosis. The dense bone is paradoxically weak/brittle, and the marrow space becomes obliterated, causing severe anemia and prompting extramedullary hematopoiesis (hepatosplenomegaly). Skull base thickening can narrow cranial nerve foramina, producing early strabismus/visual symptoms. Surviving to age 7 suggests either a milder severe (infantile AR) variant or an intermediate AR form, but the combination of marked sclerosis, cranial nerve involvement, and severe anemia pushes the case toward the severe end of the AR spectrum.

Source: Ibrahim D, Osteopetrosis. Case study, Radiopaedia.org (Accessed on 17 Feb 2026) https://doi.org/10.53347/rID-228873

Hints

• A 7-year-old girl is brought in for progressive fatigue and abnormal eye alignment that started in infancy, and her parents mention she has always seemed ‘paler’ than her siblings.
• Her parents are consanguineous but healthy, and the family history is notable for one older sister with the same condition and recurrent fractures while two brothers are unaffected, suggesting an autosomal recessive pattern.
• She developed strabismus beginning around 2 months of age, raising concern for an early process affecting the skull base and cranial nerve canals rather than a simple isolated eye-muscle problem.
• On exam she appears markedly pale and has hepatosplenomegaly, which fits with chronic bone marrow failure and compensatory extramedullary hematopoiesis.
• Plain radiographs show diffuse, symmetric increased bone density involving the skull, spine, pelvis, and long bones, meaning this is a systemic skeletal process and not a focal lesion.
• A disorder that causes generalized osteosclerosis, brittle ‘marble-like’ bones, cranial nerve compression from skull thickening, and marrow failure due to osteoclast dysfunction