Clival lesions
Differential diagnosis
| Disease | Origin | Location | Age | T2 signal | Enhancement | Calcification | Key differentiator |
|---|---|---|---|---|---|---|---|
| Chordoma | Notochordal remnants | Midline | 50-60s | Markedly high (physaliferous cells) | Moderate, heterogeneous | Sequestered bone (30-70%) | Midline + very T2 bright + destructive |
| Chondrosarcoma | Cartilage (petroclival synchondrosis) | Off-midline (paramedian) | 40-50s | High (hyaline cartilage) | Heterogeneous, peripheral/septal | Chondroid matrix - "rings and arcs" | Off-midline + chondroid calcification |
| Metastasis / plasmacytoma | Haematogenous / marrow | Variable | Variable | Intermediate | Variable, often avid | Rare | No specific matrix, often known primary |
| Ecchordosis physaliphora | Benign notochordal remnant | Midline, posterior clivus | Any age | High (CSF-like) | None | None | Non-enhancing, no destruction, intradural |
| Meningioma | Meninges | Dural surface | Middle-aged+ | Iso-low | Avid, homogeneous | Possible (hyperostosis) | Dural tail, extra-axial |
| Nasopharyngeal Ca | Nasopharyngeal mucosa | Inferior clivus | 50-60s, M > F | Intermediate | Moderate-avid | Rare | Known NPC, inferior approach |
Quick recall
- Midline = chordoma, off-midline = chondrosarcoma - this is the single highest-yield discriminator
- Both are T2 bright with calcification - location is key
- Ecchordosis physaliphora is the benign "do not touch" mimic - no enhancement, no destruction, intradural
- Chordomas express brachyury on immunohistochemistry (pathognomonic)
