Treatment of an Askin tumor: A case report and review of the literature

PET/MR of pediatric bone tumors: what the radiologist needs to know

Integrated 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. 18F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to 18F-FDG PET/computerized tomography scans. This article reviews the 18F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.

Radiological and pathological diagnosis of an incidental Askin tumor

A 53-year-old male with no significant past medical history presented with an acute traumatic fracture of his thumb. Preoperative chest radiograph before K-wire fixation demonstrated an incidental 9 cm opacity of the left lung. Chest computed tomography revealed a 6.3 cm aggressive appearing pleural-based mass with erosion and destruction of the underlying rib. The patient underwent percutaneous biopsy with interventional radiology, and pathology revealed a small round blue cell tumor with positive CD99 staining and a FUS-ERG chromosomal translocation. The patient was diagnosed with Askin tumor, a peripheral primitive neuroectodermal tumor of the thoracopulmonary region belonging to the Ewing sarcoma tumor family. Computed tomography and magnetic resonance imaging of Askin tumors may show features such as a heterogeneous soft tissue mass, pleural effusion, rib destruction, hemorrhage, necrosis, and cystic degeneration. Askin tumors typically exhibit the EWS-FLI1 fusion mutation, although FUS-ERG chromosomal translocation has been described. Both rarity and variability of Askin tumors present a diagnostic challenge for clinicians. Collaborative effort amongst radiologists and pathologists is essential for diagnosis.

Interdisciplinary Radical "En-Bloc" Resection of Ewing Sarcoma of the Chest Wall and Simultaneous Chest Wall Repair Achieves Excellent Long-Term Survival in Children and Adolescents

Introduction: Ewing sarcomas of the chest wall, historically known as "Askin tumors" represent highly aggressive pediatric malignancies with a reported 5-year survival ranging only between 40 and 60% in most studies. Multimodal oncological treatment according to specific Ewing sarcoma protocols and radical "en-bloc" resection with simultaneous chest wall repair are key factors for long-term survival. However, the surgical complexity depends on tumor location and volume and potential infiltrations into lung, pericardium, diaphragm, esophagus, spine and major vessels. Thus, the question arises, which surgical specialties should join their comprehensive skills when approaching a child with Ewing sarcoma of the chest wall. Patients and Methods: All pediatric patients with Ewing sarcomas of the chest wall treated between 1990 and 2020 were analyzed focusing on complete resection, chest wall reconstruction, surgical complications according to Clavien-Dindo (CD) and survival. Patients received neo-adjuvant chemotherapy according to the respective Ewing sarcoma protocols. Depending on tumor location and organ infiltration, a multi-disciplinary surgical team was orchestrated to perform radical en-bloc resection and simultaneous chest wall repair. Results: Thirteen consecutive patients (seven boys and six girls) were included. Median age at presentation was 10.9 years (range 2.2-21 years). Neo-adjuvant chemotherapy (n = 13) and irradiation (n = 3) achieved significant reduction of the median tumor volume (305.6 vs. 44 ml, p < 0.05). En-bloc resection and simultaneous chest wall reconstruction was achieved without major complications despite multi-organ involvement. Postoperatively, one patient with infiltration of the costovertebral joint and laminectomy required surgical re-intervention (CD IIIb). 11/13 patients were treated with clear resections margins (R1 resection in one patient with infiltration of the costovertebral joint and marginal resection <1 mm in one child with multiple pulmonary metastases). All patients underwent postoperative chemotherapy; irradiation was performed in four children. Two deaths occurred 18 months and 7.5 years after diagnosis, respectively. Median follow-up for the remaining patients was 8.8 years (range: 0.9-30.7 years). The 5-year survival rate was 89% and the overall survival 85%. Conclusion: EWING specific oncological treatment and multi-disciplinary surgery performing radical en-bloc resections and simultaneous chest wall repair contribute to an improved survival of children with Ewing sarcoma of the chest wall.