High-Yield Summary Small round blue cell tumors (SRBCTs) represent a heterogeneous group of aggressive neoplasms characterized by undifferentiated, primitive cells with overlapping histology but distinct management pathways. Accurate diagnosis hinges on integrating clinical presentation, imaging, histopathology, immunohistochemistryand molecular genetics to avoid misclassification and inappropriate treatment. Common SRBCTs in orthopaedics include Ewing sarcoma, lymphoma, rhabdomyosarcoma, neuroblastomaand […]
High-Yield Summary Chordomas are rare, slow-growing malignant tumors arising from notochordal remnants, predominantly affecting the sacrum and mobile spine, with a predilection for local recurrence rather than distant metastasis. Surgical resection with wide margins remains the cornerstone of treatment; en bloc resection offers the best chance for local control and survival. Preoperative imaging with MRI […]
High-Yield Summary Epithelioid hemangioendothelioma (EHE) of bone is a rare, intermediate-grade vascular tumor with unpredictable behavior, requiring tailored surgical management based on lesion extent and location. Diagnosis hinges on imaging combined with biopsy and immunohistochemistry, notably CD31, CD34and ERG positivity; misdiagnosis as metastatic carcinoma or angiosarcoma is common. Surgical excision with wide margins remains the […]
High-Yield Summary Adamantinoma is a rare, low-grade malignant bone tumor predominantly affecting the tibial diaphysis in young adults, requiring wide surgical excision for cure. Diagnosis hinges on imaging combined with biopsy; characteristic radiographic features include intracortical, lytic lesions with a “soap-bubble” appearance. Limb-sparing resection with clear margins is the gold standard; amputation is reserved for […]
High-Yield Summary Allografts provide biological reconstruction with potential for ligamentous and soft tissue reattachment but carry risks of nonunion, infectionand fracture. Megaprostheses offer immediate structural stability and early weight-bearing, favored in oncologic and massive bone loss cases but have higher long-term mechanical failure rates. Surgical choice hinges on patient factors, defect size, soft tissue qualityand […]
High-Yield Summary Fibrous dysplasia (FD) is a benign fibro-osseous lesion caused by postzygotic activating mutations in the GNAS gene, leading to abnormal bone remodeling and structural weakness. McCune-Albright Syndrome (MAS) combines polyostotic FD with café-au-lait skin pigmentation and endocrine hyperfunction, requiring multidisciplinary management. Surgical intervention focuses on fracture prevention, deformity correction, and functional restoration, with […]
High-Yield Summary Dedifferentiated chondrosarcoma (DDCS) is a biphasic tumor with a low-grade cartilaginous component and a high-grade non-cartilaginous sarcomatous component, demanding aggressive surgical management due to poor prognosis. Wide en bloc resection with negative margins is the cornerstone of treatment; chemotherapy and radiotherapy have limited roles but may be considered in select high-grade dedifferentiated components. […]
High-Yield Summary Pigmented Villonodular Synovitis (PVNS) is a benign but locally aggressive proliferative synovial disorder, most commonly affecting the knee and characterized by hemosiderin deposition and joint destruction if untreated. MRI is the diagnostic gold standard, showing low-signal intensity on both T1- and T2-weighted images due to hemosiderin, critical for differentiating PVNS from other synovial […]
### High-Yield Summary – Osteoid osteoma is a benign osteoblastic tumor characterized by a nidus of osteoid and woven bone surrounded by reactive sclerosis; histopathologic variants influence clinical presentation and surgical approach. – The classic nidus contains interlacing osteoid trabeculae lined by osteoblasts within a highly vascularized stroma; variants include subperiosteal, cortical, and medullary types, […]
High-Yield Summary Parosteal osteosarcoma (POS) and periosteal osteosarcoma (PeOS) are distinct surface osteosarcomas with unique biological behavior and surgical implications; POS is low-grade and well-differentiated, while PeOS is intermediate-grade and more aggressive. Accurate diagnosis hinges on imaging and biopsy correlation: POS typically presents as a densely ossified, lobulated mass attached to the cortex, whereas PeOS […]
Last Updated on January 25, 2026 by Christian Veillette
