Lab Studies:
Lab workup was significant for elevated potassium of 5.3, and elevated total bilirubin of 1.7. CBC was within normal limits.
Other Studies:
A lateral radiograph of the right knee was done and revealed a posterior soft tissue mass Case Photo #2 . An anterior-posterior view of the bilateral knees was done and did not appreciate any joint space narrowing. Subsequently, a magnetic resonance imaging (MRI) of the right knee was done and revealed a 5.1 x 4.3 x 3.0 cm peripherally enhancing mass involving the posterior right knee subcutaneous soft tissues that was considered to be a primary soft tissue sarcoma (STS) Case Photo #3 . A biopsy of the right popliteal protrusion was done and the pathology was positive for a stage 1 grade IB fibrosarcoma
Consultations:
Orthopedics/Sports Medicine was initially consulted for evaluation of a popliteal cyst that was concerning on physical exam. Ortho-oncology was then consulted for concern of a soft tissue sarcoma.
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