A 55-year-old man presents with painless progressive proptosis over 2 years. CT shows a well-encapsulated intraconal mass with smooth borders, homogeneous contrast enhancement, and no bone erosion. MRI shows high T2 signal. The MOST likely diagnosis is:
- A Lymphoma of the orbit
- B Cavernous hemangioma (orbital venous malformation) ✓
- C Optic nerve sheath meningioma
- D Rhabdomyosarcoma
Explanation
Cavernous hemangioma (now reclassified as orbital venous malformation) is the most common benign orbital tumor in adults, presenting as a slowly progressive, painless proptosis. CT shows a well-encapsulated intraconal oval mass with smooth margins, homogeneous enhancement, and no bone erosion. MRI characteristically shows high T2 signal. Progressive patchy fill-in enhancement on dynamic CT (due to slow vascular filling) is pathognomonic. Orbital lymphoma tends to cast a salmon-colored subconjunctival lesion and has heterogeneous signal. Optic nerve meningioma wraps around the optic nerve with tram-track calcification on CT. Rhabdomyosarcoma is a rapidly progressive tumor in children.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.