Presentation
Known case of osteosarcoma post resection , for follow up.
Patient Data
Modular universal tumor and revision system (MUTARS) prosthesis is seen in the right shoulder joint and the proximal humerus without hardware-related complications. Extensive calcification in the soft tissue surrounding the prosthesis is seen, the differential diagnosis would include heterotopic ossification or tumor recurrence.
Circumferential soft tissue mass lesion surrounding the proximal two-thirds of the humerus which demonstrates intermediate high T2 signal intensity and isointense T1 signal intensity with avid enhancement. The mass is involving all of the arm compartments and abutting the subclavian neurovascular bundle, the imaging features are in keeping with osteosarcoma recurrence. There are multiple suspicious axillary lymph nodes, highly worrisome for lymph node metastasis.
Case Discussion
This case illustrates the radiographic appearance of osteosarcoma recurrence. Osteosarcoma patients usually receive multimodal treatment including chemoradiotherapy and surgical resection with prosthesis placement. Follow up by radiographs is routinely performed to rule out recurrence or hardware related complications.
The presence of soft tissue calcifications on x-ray after the surgery would raise the possibility of tumor recurrence or heterotopic ossification. Comparison with prior studies is essential to differentiate between the two entities. Moreover, MRI study or PET/CT are also helpful for assessment of local recurrence.