SEARCH RESULTS FOR: Ewing-Sarcoma

Ewing Sarcoma

Ewing Sarcoma: Pathogenesis and clinical findings Demographic risk factors 85% of cases have de novo translocation mutation of EWSR1 gene on chromosome 22 to FLI1 gene on chromosome 11 Age < 30 White ethnicity Male to female 1.5-3:1 predominance EWSR1-FLI1 fusion product functions as an oncogene Tumorigenesis Ewing Sarcoma Translocation t(11;22)(q24;q12) detectable with a genetic molecular study called FISH Authors: Curtis Ostertag Nojan Mannani Reviewers: Mankirat Bhogal Michelle J. Chen Dr. Michael Monument* * MD at time of publication Well-defined histopathology Biopsy: sheets of monotonous small round blue cells with increased nuclear to cytoplasmic ratio Immunohistochemistry staining positive for CD99 (80% of cases) Diagnostic confirmation by histopathology Diagnostic confirmation by molecular genetics X-Ray findings: moth-eaten lesions, Codman triangle of elevated periosteum, or onion- skin periosteal reaction MRI findings: solid mass in bone, low T1 intensity, high T2, gadolinium enhancement, surrounding edema & soft tissue mass Malignant small round cell tumor; the second most common malignant bone tumor in adolescents and young adults. Most common in the axial skeleton (pelvis, shoulder girdle, and ribs) and diaphysis of long bones. Rapid cell turnover Tumor expansion in bone, disrupting normal tissue Possible metastasis to surrounding soft tissue Possible metastasis to lung/pleura Nodule/malignant pleural effusion Absent breath sounds, pleural signs, crackles/rales Possible metastasis to bone marrow Replacement of normal hematopoietic tissue, including megakaryocytes (source of platelets) Thrombocytopenia Petechiae/purpura Peritumoral edema Swelling Stiffness Invasion of cancer cells to distant tissues via bloodstream Tumor expands toward skin surface Palpable lump Tumor secretes ↑ vascular endothelial growth factor (VEGF) ↑ Generation of immature blood vessels which have ↑ permeability ↑ Expression of inflammatory cytokines (i.e. IL-6) Massive metabolic demand from cancer cells Energy starved state Systemic constitutional symptoms including fevers, chills, weight loss, night sweats, fatigue ↓ Distractions at night brings ↑ attention to pain Adrenal glands naturally release ↓ cortisol throughout the day with the lowest levels at night. Lack of anti- inflammatory properties from cortisol ↑ pain Potential gravity- related ↑ in tumor- related pressure & ↑ in active bone remodeling Tumour growth stretches periosteum (connective tissue around bone) causing osteolysis, inflammation, nerve infiltration, edema, structural weakening (microfractures) Pain that worsens at night Limp Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published Dec 30, 2024 on www.thecalgaryguide.com