Extraskeletal Ewing's sarcoma is a tumor that occurs in soft tissues and is histologically identical to Ewing's sarcoma of bone.

bubble_chart Pathological Changes

1. Gross examination reveals a brown cut surface, which may show extensive hemorrhage, necrosis, indistinct borders, and an incomplete capsule.

2. Microscopic examination shows uniform small round cells with scant cytoplasm, indistinct borders, and tight arrangement. The nuclei are round with clear nuclear membranes, finely granular chromatin, and occasional eosinophilic nucleoli. Mitotic figures are relatively rare.

bubble_chart Clinical Manifestations

It is commonly seen in young adults, with 85% of cases occurring between the ages of 20 and 30, and the incidence is similar in both males and females. The tumors are frequently located in the soft tissues of the limbs and paravertebral regions. These tumors grow rapidly, tend to recur after excision, and often metastasize early, commonly to the lungs and bones. The tumors present as irregular nodules or lobulated masses, often tightly adherent to adjacent tissues, and are soft and fragile in texture.

bubble_chart Treatment Measures

Due to the infiltrative growth of the tumor, it is difficult to perform a wide resection, and the tumor is highly prone to recurrence postoperatively. Additionally, early lung metastasis is common, making it challenging to control this tumor solely through surgical means. However, this tumor is sensitive to chemotherapy and radiotherapy, and treatment should primarily focus on these modalities. Once a pathological diagnosis is confirmed, systemic chemotherapy should be initiated as soon as possible. Based on our experience, tumors approximately 10 cm in diameter can completely disappear after 1 to 2 cycles of chemotherapy. Commonly used chemotherapeutic agents include doxorubicin, cyclophosphamide, and vincristine. For cases where surgical resection has been performed, it is advisable to supplement chemotherapy with radiotherapy at the surgical site.

It should be differentiated from rhabdomyoma, neuroblastoma, and lymphoma.