Complete tumor necrosis after neoadjuvant chemotherapy defines good responders in patients with Ewing sarcoma.

BACKGROUND: Survival in patients who have Ewing sarcoma is correlated with postchemotherapy response (tumor necrosis). This treatment response has been categorized as the response rate, similar to what has been used in osteosarcoma. There is controversy regarding whether this is appropriate or whether it should be a dichotomy of complete versus incomplete response, given how important a complete response is for in overall survival of patients with Ewing sarcoma. The purpose of this study was to evaluate the impact that the amount of chemotherapy-induced necrosis has on (1) overall survival, (2) local recurrence-free survival, (3) metastasis-free survival, and (4) event-free survival in patients with Ewing sarcoma. METHODS: In total, 427 patients who had Ewing sarcoma or tumors in the Ewing sarcoma family and received treatment with preoperative chemotherapy and surgery at 10 international institutions were included. Multivariate Cox proportional-hazards analyses were used to assess the associations between tumor necrosis and all four outcomes while controlling for clinical factors identified in bivariate analysis, including age, tumor volume, location, surgical margins, metastatic disease at presentation, and preoperative radiotherapy. RESULTS: Patients who had a complete (100%) tumor response to chemotherapy had increased overall survival (hazard ratio [HR], 0.26; 95% CI, 0.14-0.48; p < .01), recurrence-free survival (HR, 0.40; 95% CI, 0.20-0.82; p = .01), metastasis-free survival (HR, 0.27; 95% CI, 0.15-0.46; p ≤ .01), and event-free survival (HR, 0.26; 95% CI, 0.16-0.41; p ≤ .01) compared with patients who had a partial (0%-99%) response. CONCLUSIONS: Complete tumor necrosis should be the index parameter to grade response to treatment as satisfactory in patients with Ewing sarcoma. Any viable tumor in these patients after neoadjuvant treatment should be of oncologic concern. These findings can affect the design of new clinical trials and the risk-stratified application of conventional or novel treatments.

Multifocal giant cell tumor of the carpus: Unusual presentation. Case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Giant cell tumors (GCTs) of bone in the carpus are rare. Carpal GCTs are usually solitary lesions; multifocal involvement is exceptional. These lesions have a higher risk of local recurrence after intralesional curettage than those in other body areas. CASE PRESENTATION: We present a case of a 28-year-old male with a six-month history of a palpable mass in the dorsal aspect of the left wrist. Physical examination revealed a 2 cm, mildly tender mass. Magnetic resonance revealed a large intermediate signal lesion involving completely hamate bone and the distal portion of the triquetrum. Histological examination confirmed a giant cell tumor of the carpus. The patient underwent en-bloc resection of the hamate bone extending to the distal part of the pyramidal. The defect was reconstructed using polymethylmethacrylate cement (PMMA), and intercarpal arthrodesis with the capitate was achieved. Follow-up at 18 months revealed a good clinical evolution, wrist range of motion of 30° of extension, 30° of flexion, and 10° of ulnar and radial deviation without evidence of tumoral recurrence. CLINICAL DISCUSSION: The current literature suggests a high incidence of local recurrence in carpal GCT, so wide excision with carpal arthrodesis is recommended, especially in Campanacci III and multifocal involvement. CONCLUSION: Carpal GCT is exceptional, mainly affecting the hamate, capitate, and scaphoid. Most literature supports wide excision of carpal GCT owing to the high recurrence rate with intralesional procedures.