Chondrosarcoma - sphenoid wing

CT and MRI images demonstrate an extraaxial lesion arising from just lateral to the clivus and cavernous sinus. It is of mixed density on CT with regions of calcifications.

On MRI the lesion is heterogeneous in signal with the more medial component demonstrated high T2 signal and variegated contrast enhancement, without restricted diffusion.

Features are consistent with a chondrosarcoma (histologically proven). The off-midline location and ring-like calcification makes a chordoma much less likely.

Final Diagnosis:

Sphenoid wing lesion, excision: Chondrosarcoma, low-grade (2/3).

Microscopic Description: 

Sections show a moderately cellular cartilage-forming neoplasm with large areas of tumor necrosis. The tumor cells are round to polygonal with hyperchromatic nuclei and are embedded in hyaline chondromatous matrix. There are foci, however, in which the tumor cells are stellate to spindle in shape, have slightly vacuolated cytoplasm and are embedded in myxoid stroma. The tumor cells are diffusely and strongly positive for S-100 protein and negative for EMA and cytokeratin.