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Updated: Aug 25, 2026
Surgical Treatment of an Endolymphatic Sac Tumor
Published on: May 26, 2023
[Ewing's sarcoma]
Takahiro Goto1, Takahiro Hozumi, Taiji Kondo
1Dept. of Orthopaedic Surgery and Musculoskeletal Oncology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Hon-Komagome, Bunkyo-ku, Tokyo 113-8677, Japan.
Insights
Ewing's sarcoma is a high-grade bone malignancy in children, characterized by pain and swelling. Treatment involves a multimodal approach including chemotherapy, surgery, and radiotherapy for optimal outcomes.
Area of Science:
- Pediatric Oncology
- Skeletal Malignancies
Context:
- Ewing's sarcoma represents 6.8% of primary malignant bone tumors.
- Primarily affects children aged 5-15 years.
- Characterized by pain, swelling, and elevated inflammatory markers.
Purpose:
- To provide a comprehensive overview of Ewing's sarcoma.
- To detail diagnostic imaging and histological features.
- To outline current treatment strategies and emerging therapies.
Summary:
- Radiological findings include permeative bone destruction and periosteal reaction.
- Histology reveals sheets of small round cells with glycogen granules.
- Immunohistochemistry shows positivity for vimentin and CD99.
- Genetic analysis identifies the EWS/FLI-1 fusion gene in t(11;22) translocation.
Impact:
- Multimodal treatment combining chemotherapy, surgery, and radiotherapy is standard.
- Neoadjuvant chemotherapy reduces tumor volume and eradicates micrometastasis.
- High-dose chemotherapy with autologous bone marrow transplantation shows promise for poor-prognosis cases.
Abstract:
Ewing's sarcomas account for 6.8% of all primary malignant bone tumors and are probably a neurogenic, undifferentiated, high-grade malignancy, which usually affects the bones of children 5-15 years of age. Pain and swelling are the most common symptoms. Increase of CRP and erythrocyte sedimentation rate, leucocytosis, and anemia are frequently seen. Radiologically, they show permeative bone destruction on plain radiographs. When arising in the diaphysis of long bones, laminated, "onion-skin" periosteal reaction is seen. The tumor shows muscle density on CT, iso-signal intensity on T1-weighted MR images, and high signal intensity on T2-weighted MR images. Intramedullary invasion and skip lesions can be detected on MR images. Histologically, the tumor is uniformly composed of sheets of small round cells closely packed and without any matrix product. Glycogen granules are demonstrated in the cytoplasm by periodic acid-Schiff (PAS) and diastase reactions. Immunohistochemically, Ewing's sarcomas are positive for vimentin and MIC-2 gene product (CD99). Reciprocal translocation, i.e., t(11;22) (q24;q12), is seen in the tumor cells. EWS/FLI-1 fusion gene can be demonstrated, which can be a complementary method in diagnosing this tumor. Because Ewing's sarcomas are chemosensitive and radiosensitive, they are treated by a combination of chemotherapy, surgery, and radiotherapy. Neoadjuvant chemotherapy consists of preoperative chemotherapy and postoperative chemotherapy. Preoperative chemotherapy aims at eradicating distant micrometastasis, reducing the primary tumor volume, and evaluating the efficacy of the chemotherapeutic agents. Surgery is performed as a local treatment by excising the tumor using the wide procedure. If surgery is impractical, curative radiotherapy is performed instead of excision. When surgery is performed without complete wide procedure, adjuvant radiotherapy is carried out to eradicate the residual tumor cells. Postoperative chemotherapy aims to eradicate the distant micrometastasis. Recently, myeloablative, high-dose chemotherapy followed by autologous bone marrow transplantation is being attempted for poor-prognosis patients and good results have been reported.
