https://orcid.org/0000-0002-3344-421X
Abstract
Ewing sarcoma is a rare malignant bone tumour that predominantly affects long and flat bones; mandibular involvement is exceptional. We report the case of a 14-year-old boy presenting with a firm, painless right cheek mass that progressively enlarged over 7 months. Clinical examination revealed a mass extending ~9 cm intraorally. The patient underwent surgical excision via vestibular hemimandibulectomy, followed by immediate reconstruction using a chondrocostal graft fixed to a titanium plate, alongside neoadjuvant and adjuvant chemotherapy. Histopathological and immunohistochemical analyses confirmed the diagnosis. At the 6-month follow-up, there has been no evidence of recurrence, and the patient has maintained satisfactory facial symmetry and oral function. This case highlights the importance of including Ewing sarcoma in the differential diagnosis of paediatric cheek masses and demonstrates that chondrocostal grafting is a viable reconstructive option in growing patients.
Introduction
Ewing sarcoma is a rare malignant bone tumour belonging to the neuroectodermal tumour family, accounting for <1% of all childhood cancers and primarily affecting children and adolescents. Its incidence is estimated at one to two cases per million per year. Cervicofacial location is unusual (1%–4% of cases), and mandibular involvement remains exceptional. To date, only a few dozen cases of mandibular Ewing sarcoma have been reported in the international literature. This rarity often leads to diagnostic delays, compromising the patient’s prognosis due to the tumour’s aggressive nature, which necessitates rapid, multidisciplinary management. We report a case of mandibular Ewing sarcoma successfully managed with primary autologous chondrocostal bone grafting following tumour resection [1–4].
Case report
A 14-year-old boy presented with a seven-month history of progressive right cheek swelling and V3 hypoesthesia. Clinical examination revealed a hard, painless mass extending ~9 cm intraorally (Fig. 1A). While this clinical measurement reflected significant overlying reactive soft tissue swelling, computed tomography (CT) imaging identified the core bony lesion as 7.5 cm (75 × 42 × 30 mm). Five incidental café-au-lait spots were noted on the lower limbs and abdomen; neurofibromatosis type 1 was clinically excluded due to absent syndromic features. Orthopantomogram and CT showed a lytic, necrotic lesion in the right mandibular ramus extending to the condyle, infiltrating regional muscles, with no distant metastases (Figs 2 and 3).
(A) Frontal clinical photograph of a teenage boy showing a firm, painless swelling on the right side of the lower face and cheek. (B) Postoperative frontal photograph at 6 months showing restored facial symmetry and healing.
Axial and coronal CT scans displaying a large, destructive lytic lesion in the right mandibular ramus with infiltration of surrounding soft tissues and extension to the condylar process.
Panoramic dental radiograph revealing a radiolucent, expansile lesion in the right mandibular ramus with cortical thinning and no sclerotic margins, suggestive of malignancy.
Biopsy confirmed a CD99-positive Ewing sarcoma. The patient received nine cycles of vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (VDC-IE) induction chemotherapy (Euro-Ewing-99 protocol), resulting in tumour stabilization. He subsequently underwent vestibular hemimandibulectomy. The excised specimen measured 8 cm, representing the true tumour dimensions plus 1 cm macroscopic safety margins. Reconstruction was achieved using a harvested chondrocostal graft rigidly fixed to a titanium reconstruction plate (Fig. 4). Maxillomandibular fixation ensured initial occlusion. Final histopathology confirmed an R0 resection with no viable residual tumour cells. Adjuvant chemotherapy (VC/IE cycles) was subsequently completed (Fig. 5).
Postoperative panoramic radiograph showing a titanium reconstruction plate and chondrocostal bone graft successfully bridging the right mandibular defect and restoring mandibular continuity.
Gross pathology photograph of the resected right hemimandible specimen displaying the tumour mass with clear surgical margins.
At the 6-month follow-up, clinical and radiological assessments showed no recurrence. The patient exhibited stable occlusion, satisfactory facial symmetry, and a mouth opening of 35 mm. The chest wall donor site healed uneventfully without deformity or respiratory compromise (Fig. 1B).
Discussion
Mandibular Ewing sarcoma is rare (<1% of cases) and frequently misdiagnosed as odontogenic pathology, delaying treatment. Definitive diagnosis requires histopathology and cytogenetics, notably the t(11;22) translocation. Management mandates multidisciplinary care: neoadjuvant chemotherapy to reduce tumour volume and eradicate micrometastases, followed by wide surgical resection (margins >2 cm) to achieve R0 status [5–7].
Mandibular reconstruction aims to restore continuity, function, and aesthetics [8]. While the vascularized fibula free flap is currently considered the gold standard for large mandibular defects due to its reliable blood supply and capacity for osseointegration [2, 9], non-vascularized chondrocostal grafts offer distinct advantages in selected paediatric cases. Firstly, the cartilaginous component possesses intrinsic growth potential, which is crucial for maintaining condylar function and facial symmetry in growing patients [10]. Secondly, this approach avoids the prolonged operative time, microsurgical complexity, and donor-site morbidity associated with free tissue transfer. Thirdly, non-vascularized grafts can successfully integrate even in the context of adjuvant chemotherapy, provided rigid fixation (e.g. titanium plates) and a well-vascularized soft tissue envelope are maintained.
However, limitations must be acknowledged. Non-vascularized grafts carry a higher risk of partial resorption or fracture compared to vascularized bone. Furthermore, they offer less predictable outcomes for future dental implant placement in large defects. Therefore, the choice between a vascularized and non-vascularized approach must be individualized, carefully weighing defect size, patient age, growth potential, and the anticipated need for adjuvant therapies.
Craniofacial Ewing sarcoma carries a better prognosis than axial or metastatic disease. Tailored reconstruction is vital for optimal long-term survival and quality of life [11, 12].
Conclusion
Mandibular Ewing sarcoma is a rare paediatric malignancy requiring rapid, multidisciplinary intervention. This case highlights that immediate reconstruction with a chondrocostal autograft is a viable, effective alternative to vascularized free flaps in selected adolescents. It successfully restores mandibular continuity and function while accommodating facial growth, offering a less morbid surgical profile without compromising oncological safety.
Conflicts of interest
The authors declare no conflicts of interest.
Funding
No funding was received for this study.
References
David TT, Youssouf F, Mory K et al. La reconstruction mandibulaire immédiate dans la prise en charge des tumeurs odontogéniques à mopti. Health Sci Dis
