Surgical management of pelvic Ewingís sarkoma: a case report

Abstract

INTRODUCTION Ewing’s sarcoma is a rare type of bone and soft tissue malignancy. It can also metastasize to other areas of the body. While Ewingís sarcoma can occur at any time, it most commonly develops during puberty. The pelvis is one of the primary sites of Ewing’s sarcoma and is associated with poorer prognosis. CASE PRESENTATION In July 2021, 20-year-old woman was referred to our hospital due to severe left hip pain, lasting half a year. The patient was consulted by an orthopaedic oncologist due to a suspicion for a malignant tumor. In August 2021, MRI of lumbar spine and pelvis showed that a mass occupied the left side of sacrum and hip bone. In September 2021, pulmonary CT showed three solitary masses. Whole body PET showed moderately metabolic left pelvis tumor and metabolic inactive neoplastic changes in the lungs. A biopsy was performed and the patient was diagnosed with Ewing’s sarcoma,G4. Chemotherapy was initiated by the EuroEwing2012 protocol. In March 2022, PET scan was repeated to evaluate the dynamics: a tumor was significantly decreased but the metabolic activity remained. In May 2022, a partial resection of the iliac wing and aposterior sacral laminectomy were performed. Resection edges were clear. Operating together with neurosurgeons, iliac wing and vertebral bodies osteosynthesis was performed with screws and reinforced with rods, bone defect was corrected with fibular allografts. Histological examination confirmed the pre-operative clinical diagnosis - Ewing’s sarcoma pT2N0M1 G4 IVB, necrosis>99%. Postoperative radiation therapy was started, followed by a bone marrow transplant. At present, treatment is complete, there is no evidence to suspect relapse and metastasis. The functional results are great and follow-up is applied every 3 months.