Case contribution: Dr Radhiana Hassan
- A 33 years old Malay lady
- presented with mass at the right eye
- physical examination shows a huge orbital mass involving the supra orbital, forehead, temporal, preauricular and zygomatic region
- proptosis of right eyeball with necrosis of cornea
- hard and non tender, at certain areas it is crusted and inflamed.
- deformity of lateral walls.
- left eye is intact.
- cervical nodes not palpable.
- Skull radiograph in OM projection shows soft tissue opacity overlying the right orbital region.
- Ill-defined lytic lesion is also seen of the adjacent bone
CT scan findings:
- A destructive lytic lesion of the right zygoma (red arrows) with huge surrounding soft tissue mass.
- The soft tissue mass infiltrate the right orbital cavity causing right proptosis.
- Infiltration of the right optic nerve and extra-ocular muscles sparing the right medial rectus.
- Bony spiculations (yellow arrows) are noted within the mass radiating from the zygomatic bone.
Final diagnosis: Osteosarcoma of right zygomatic bone (HPE proven)
- Osteosarcoma is a primary malignant neoplasm of the bones
- greatest predilection for metaphyses of long bones
- osteosarcoma of craniofacial bones is uncommon representing only 1% of tumours of head and neck region
- the commonly involved bones in order of frequency are jaw bones, palate and skull vault. Involvement of zygomatic bone is rare
- Typically occur in 3rd to 4th decades, equal sex distribution
- radiologically 2/3 of craniofacial osteosarcoma is osteolytic
- periosteal reaction is also not frequently reported in craniofacial osteosarcoma
- Local recurrence is high and metastasis to other organs occurs rarely, unlike the long bones osteosarcoma
- Five-year survival rate is 25%-35% after radical resection
Progress of patient:
- started on chemotherapy
- a repeat CT scan 2 months later shows reduction in the size of the mass
- patient refused operation and opted for conservative management.
- Last review patient presented with multiple lung metastasis