November 14, 2019
A 26-year-old woman with progressively worsening bilateral vision loss and papilledema on fundoscopy
Camurati-Engelmann Disease
- Background:
- Camurati‐Engelmann disease (CED), also known as progressive diaphyseal dysplasia (PDD), is a rare autosomal dominant bone dysplasia. It usually begins in childhood and almost always develops before the age of 30 years.
- It occurs from a defect in the TGFB1 gene in most patients.
- Clinical Presentation:
- Pain in the extremities is the most common clinical symptom. Other common symptoms include waddling gait, easy fatigability, muscle weakness, and cranial nerve impairment.
- Optic nerve compression is attributed to bony overgrowth of the orbit, optic canal stenosis, and increased ICP.
- Most patients with the TGFB1 gene mutation are symptomatic, although specific manifestations may vary among affected individuals. A small proportion of patients can be asymptomatic.
- Key Diagnostic Features:
- Progressive symmetric diaphyseal hyperostosis of the lower extremities, which may expand to the fibulae, humeri, ulnae, and radii; as the disease progresses, the metaphyses may become affected as well, but the epiphyses are spared.
- Over 50% of patients with CED will demonstrate skull base involvement; 25% of this population experience cranial nerve dysfunction, including optic neuropathy and papilledema.
- Affected regions show high uptake with Tc99-MDP bone scintigraphy representing osteoblastic activity.
- Differential Diagnoses:
- fibrous dysplasia: tends to present as an asymmetric, expansile lesion with ground-glass matrix and intact overlying bone
- Paget disease: typically affects older patients, with “cotton-wool” thickening of the cortical skull
- sclerosing metastases: present as asymmetric, irregular foci of the skull, commonly associated with soft-tissue masses
- osteopetrosis: common at sites of endochondral ossification; widening of metaphyses of long bones
- Van Buchem disease (hyperostosis corticalis generalisata): presents with large, overbearing mandible and is less likely to manifest as circumferential skull enlargement
- Treatment:
- Drug treatment: glucocorticoids and bisphosphonates, although efficacy has yet to be established through randomized controlled trials
- Surgical decompression: primary method of management for progressive symptomatic skull base involvement
- Gene therapy: may present an alternative method of treatment for patients
