Preserved walking function without postoperative reconstruction for pelvic Ewing's sarcoma: a case report

Abstract

Background: Ewing's sarcoma is a primary bone tumor predominantly observed in children and adolescents, necessitating a multidisciplinary treatment approach. While localized cases have a 5-year survival rate of 60-70%, the prognosis is significantly worse in pelvic advanced cases with metastasis. Moreover, pelvic Ewing's sarcoma has the unique problem of leading to high rates of postoperative infection.

Case presentation: We present the case of a Japanese 14-year-old boy with left iliac Ewing's sarcoma and multiple metastases. At the initial visit, imaging revealed a large tumor in the left iliac bone with extraosseous extension and metastasis to multiple sites. Neoadjuvant chemotherapy resulted in significant tumor reduction. Surgical resection was performed without pelvic ring reconstruction to enable early postoperative chemotherapy and minimize postoperative infection risk. Despite complete abductor muscle removal, the patient achieved a stable gait postoperatively by centering the load axis.

Conclusion: Our case highlights the successful management of a left iliac Ewing's sarcoma with multiple metastases, with a focus on functional preservation and infection risk reduction. Pelvic ring reconstruction was not performed to avoid postoperative complications, emphasizing the importance of early postoperative chemotherapy. The patient achieved a stable gait postoperatively, demonstrating the potential benefits of this approach in similar cases.

Keywords: Ewing’s sarcoma; Infection; Pelvic; Pelvic ring reconstruction.

Fig. 1

Imaging findings at the first visit to our hospital. a X-ray showing a tumor in the left iliac bone with osteosclerosis and osteolysis. b MRI showing a tumor in the left iliac bone, with a conspicuous extra-bone mass in the gluteus medius muscle. c–h PET–CT showing accumulation in the C2 vertebra (e), right lung (f), L2 vertebra (g), and right femur (h), in addition to the primary tumor (d). CT, computed tomography; MRI, magnetic resonance imaging; PET–CT, positron emission tomography–computed tomography

Fig. 2

a–c Imaging findings after five courses of VDC/IE chemotherapy. a MRI showing the presence of an extra-bone mass within the gluteus medius muscle, although reduced in size. b, c PET–CT showing residual accumulation of primary tumor but disappearing of metastases. d, e Intraoperative findings of wide excision for the left iliac malignant bone tumor. d Before excision, an extra-bone mass was palpable within the gluteus medius muscle and resected together with the iliac wing. e Osteotomy was performed on the sacrum slightly medial to the sacroiliac joint and just above the acetabulum. f Postoperative X-ray. Pelvic ring reconstruction was not performed. PET–CT,  positron emission tomography–computed tomography; VDC/IE, Vincristine doxorubicin cyclophosphamide/Ifosfamide etoposide

Fig. 3

a Progress of postoperative plain X-ray imaging. The patient’s left hip was gradually centralized to the pelvic center. b There was no remarkable Trendelenburg sign at 20 months after the excision

Fig. 4

Schematic representation of this case. Centralization of the left hip joint without pelvic ring reconstruction shortened the lever arm between the spine and hip joint. Therefore, lower abductor muscle strength is required for stable walking. This figure is our own work