Chondrosarcoma of the patella: A case report

Primary and Metastatic Bone Tumors of the Patella: Literature Review and Institutional Experience

BACKGROUND

Patellar tumors are rare but certainly must be considered in the differential diagnosis in patients with knee pain. Diagnosis can be challenging as often patellar neoplasms are confused with benign conditions and their clinical presentation is usually not specific. We performed an institutional and a literature review to determine what are the most common tumors affecting the patella and what is the best management.

METHODS

This is a case series from our institution including all patients with benign, malignant, and metastatic patellar neoplasms. Charts were reviewed for patient demographics, clinical presentation, pathology characteristics, radiographic classification, and oncologic and functional outcomes.

RESULTS

Twenty-four patients were identified; twelve patients had benign lesions, 10 metastatic and 2 primary malignant tumors. Chondroblastoma and Giant Cell Tumor were the most common tumors. Management of benign lesions with intralesional curettage and packing with bone graft or cement demonstrated excellent results with no local recurrence. In terms of malignant tumors, the spectrum of treatment is variable; it could range from medical management alone or in combination with surgical procedures to total patellectomy with reconstruction of the extensor mechanism.

CONCLUSION

Patellar tumors should be part of the differential in patients with chronic knee pain that does not respond to initial conservative interventions. Recurrence rate with intralesional curettage and bone grafting or cement packing is very low and therefore should be the treatment of choice for benign intraosseous neoplasms. Resection with negative margins in malignant neoplasms or bone metastasis decreases local recurrence but only in the former group there is a potential impact in survival.

Bacteriophage-mediated therapy of chondrosarcoma by selective delivery of the tumor necrosis factor alpha (TNFα) gene

Chondrosarcoma is a cartilage-forming bone tumor, well known for intrinsic resistance to chemotherapy and radiotherapy. We have designed a targeted chondrosarcoma gene therapy using a bacteriophage (phage) particle to deliver therapeutic genes. Phage has no tropism for mammalian cells, allowing engineered phage to be targeted to specific cell surface receptors in cancer. We modified the phage capsid to display the RGD4C ligand on the pIII minor coat proteins to specifically bind to αvβ3 or αvβ5 integrin receptors. The endosomal escape peptide, H5WYG, was also displayed on recombinant pVIII major coat proteins to enhance gene delivery. Finally, a human tumor necrosis factor alpha (TNFα) therapeutic transgene expression cassette was incorporated into the phage genome. First, we found that human chondrosarcoma cells (SW1353) have high expression of αvβ3, αvβ5 integrin receptors, and both TNFα receptors. Targeted particle encoding a luciferase reporter gene efficiently and selectively mediated gene delivery to these cells. When SW1353 cells were treated with the targeted particle encoding a TNFα transgene, significant cell killing was evident and was associated with high expression of TNFα and apoptosis-related genes. In vivo, mice with established human chondrosarcoma showed suppression of tumors upon repetitive intravenous administrations of the targeted phage. These data show that our phage-based particle is a promising, selective, and efficient tool for targeted chondrosarcoma therapy.

Innovative chest wall reconstruction with a locking plate and cement spacer after radical resection of chondrosarcoma in the sternum: A case report

BACKGROUND

Chondrosarcoma, a cartilage matrix producing tumor, is the second most commonly observed primary bone tumor after osteosarcoma, accounting for 15% of all chest wall malignancies. We herein report the case of a patient with chondrosarcoma of the sternum and our management of the chest wall defects that presented following radical tumor resection.

CASE SUMMARY

A 31-year-old patient presented to our hospital with dull pain and a protruding mass overlying the chest for 3 mo. The presence of nocturnal pain and mass size progression was reported, as were overhead arm elevation-related limitations. Computed tomography showed a focal osteoblastic mass in the sternum with bony exostosis and adjacent soft tissue calcification. Positron emission tomography-computed tomography revealed hypermetabolic activity with a mass located over the upper sternum. Magnetic resonance imaging showed a focal ill-defined bony mass of the sternum with cortical destruction and periosteal reaction. Preoperative biopsy showed a consistent result with chondrosarcoma with immunohistochemical positivity for S100 and focal positivity for IDH-1. The grade II chondrosarcoma diagnosis was confirmed by postoperative pathology. The patient underwent radical tumor resection and chest wall reconstruction with a locking plate and cement spacer. The patient was discharged 1 wk after surgery without any complications. At the 1-year follow-up, there was no local recurrence on imaging. The functional scores, including Constant Score, Nottingham Clavicle Score, and Oxford Shoulder Score, showed the absence of pain in the performance of daily activities or substantial functional disabilities.

CONCLUSION

The diagnosis of chondrosarcoma must be considered when chest wall tumors are encountered. The surgical reconstructive materials, with a locking plate and cement spacer, used in our study are cost-effective and readily-available for the sternum defect.