Severe presentation of non-ossifying fibroma of the femur in osteoglophonic dysplasia

Abstract

Osteoglophonic dwarfism, also known as osteoglophonic dysplasia (OD), is an uncommon skeletal dysplasia with an autosomal dominant mode of inheritance, which equally affects boys and girls. OD is saliently featured by craniosynostosis, dysmorphic facial features, impacted mandibular teeth, rhizomelic limb shortening and non-ossifying fibromas habitually at the metaphyseal regions, which usually disappear after skeletal maturity. The long bones in OD are portrayed by this distinguishable 'hollowed-out' appearance with metaphyseal cystic defects that have a natural history of spontaneous resolution. We report a case of a rare and unusual presentation of OD in a 23-year-old woman whom has been diagnosed with OD during her early childhood. She presented with a progressively enlarging right thigh swelling associated with pain for the past 1 year. Her right femur plain radiograph revealed diffuse lysis of the whole femur with cortical thinning. MRI revealed multiple bilateral femur benign cystic lesion synonymous with a severe spectrum of OD. She was started on a trial of oral bisphosphonates, which led to a significant improvement in pain.

Keywords: congenital disorders; orthopaedics; paediatric oncology.

Figure 1

Right thigh diffuse swelling with no overlying skin changes.

Figure 2

(A) Bilateral femur radiograph showing multilocular expansile lytic lesions with sclerotic rim and narrow transition zone in the distal metadiaphyseal regions with cortical thinning. (B) Coronal turbo inversion recovery magnitude (TIRM) MRI image of bilateral femur showing hyperintense multilocular expansile lesions in the distal metaphyseal regions.

Figure 3

(A) Coronal T1 fat saturation image of the right femur showing progressive lesion up until the proximal diaphysis. (B) Lytic lesion in the left distal femur metadiaphyseal region relatively similar with fluid-fluid levels suggestive of a pathological fracture.

Figure 4

(A) Bilateral femur plain radiograph showing progressive expansion of lytic lesions over the right femur with marked cortical thinning and progression of lytic lesion in the distal left femur. (B) Right lateral femur radiograph with worsening lytic lesion and progressive cortical thinning.

Figure 5

Right femur radiograph postbisphosphonate therapy showing thickening of the posterior-medial femoral cortex.