Presentation
Referred patient for imaging after detecting sacral mass.
Patient Data
Midline, grossly expansile, sacral mass that involves sacral segments S2-S5. There is no transarticular extension into the sacroiliac articulations. It demonstrates heterogeneous high signal intensity on STIR sequences and homogeneous low signal intensity on T1 sequences compared to normal bone marrow. There is effacement of the presacral soft tissues but with no evidence of frank soft tissue invasion.
Case Discussion
This case most likely represents a chordoma; however, based solely on imaging and without biopsy, a giant cell tumor cannot be completely excluded.
Chordomas are rare primary malignant bone tumors that originate from embryonic remnants of notochord foci, most commonly arising in the sacral region. The 5-year survival rate in adults is 50-75% with a recurrence rate of 70% after excision 1.