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Patient: 19 year old male |
History: 19 year old boy with left tibial osteosarcoma status post excision, prothesis placement, and chemotherapy. Routine follow-up after completion of therapy.
Nine months after completion of therapy:
Figure 1 Figure 2
Corresponding radiographs
Figure 3 Figure 4
What is your interpretation of this study?
1 year after completion of therapy
Figure 5 Figure 6
Corresponding radiographs
Figure 7 Figure 8
What is you interpretation of this study and how has it changed since the prior study?
Corresponding CT images (1 year after completion of therapy)
Figure 9
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Image Size:[small][as-submitted]
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Findings: Bone Scinitgraphy (9 months after completion of therapy)
RADIOPHARMACEUTICAL: 18.3 mCi Tc-99m MDP i.v.
No evidence of osseous metastatic disease.
Partially visualized new radiotracer uptake within the left fourth and fifth metatarsals which is likely secondary to altered biomechanical stress. If clinically indicated, x-rays of the foot can be obtained for further evaluation.
Radiographs (9 months after completion of therapy)
No evidence of tumor recurrence status post osteosarcoma resection with modular reconstruction.
Bone Scintigraphy (1 year after completion of therapy)
RADIOPHARMACEUTICAL: 20.2 mCi Tc-99m MDP i.v.
Interval development of abnormally increased radiotracer uptake in the soft tissues of the left knee medial to the distal left femur.
Interval decrease of the previously noted radiotracer uptake in the left foot is consistent with improvement in stress change on that foot from altered weight bearing.
Radiographs (1 year after completion of therapy)
Incompletely seen constrained modular type total left knee arthroplasty. The visualized instrumentation is intact without surrounding lucency or periprosthetic fracture. There is soft tissue prominence with increased ossific densities in the popliteal fossa.
CT Left Lower Extremity (1 year after completion of therapy)
Lobulated soft tissue mass containing calcification posterior to the medial femoral condyle. This mass measures 6.4 x 4.5 cm transaxially and 6.0 cm craniocaudal and is located deep to the semitendinosus tendon and inseparable from the semimembranosus muscle. The mass is separate from the neurovascular bundle and no adjacent bone destruction is seen. There has been excision of the proximal tibia with prosthetic replacement and a constrained left knee arthroplasty. |
DDx: Reccurent osteosarcoma in the soft tissues
Myositis ossificans |
Diagnosis: Recurrent Osteosarcoma (Surgical Pathology) |
References: Bacci et al. "Treatment and outcome of recurrent osteosarcoma: experience at Rizzoli in 235 patients initially treated with neoadjuvant chemotherapy." Acta Oncol 2005;44(7):748-55. |
Comments: No comments posted. |
Additional Details:
Case Number: 245553Owner(s): Keith Fischer and Andrew HombLast Updated: 02-07-2013 The reader is fully responsible for confirming the accuracy of this content. |