Ewing sarcoma of the great toe: a rare case report

Ewing sarcoma (ES) rarely arise in the toes, where nonspecific pain and swelling can mimic benign conditions, delaying diagnosis. Early recognition is critical because modern multimodal therapy can achieve limb preservation and high rates of disease control even at unconventional sites.

A healthy 22-year-old man developed progressive pain and swelling of the left hallux after partial nail excision for a presumed ingrown toenail. The wound failed to heal, evolving into a friable 3 × 3 cm dorsal mass. Radiography and MRI demonstrated an aggressive lytic lesion destroying the distal phalanx with soft-tissue extension. Incisional biopsy revealed small round blue cells strongly positive for CD99, and fluorescence in situ hybridization confirmed an EWSR1 rearrangement consistent with ES. Staging PET-CT showed no metastases. The patient received six cycles of vincristine-doxorubicin-cyclophosphamide alternating with ifosfamide-etoposide, followed by partial amputation of the distal phalanx with clear margins. Histology showed 98% tumor necrosis. Adjuvant chemotherapy was completed uneventfully. At 12-month surveillance, MRI and PET-CT showed no local recurrence or distant spread, and the patient had painless, functional ambulation.

This case highlights three key lessons: 1. Persistent or atypical digital lesions warrant oncologic evaluation. Soft-tissue masses that do not resolve after routine care should prompt advanced imaging and biopsy. 2. Molecular confirmation is pivotal. Detection of an EWSR1-FLI1 family fusion secures the diagnosis and guides therapy. 3. Neoadjuvant chemotherapy enables limb-sparing surgery. Pre-operative tumor shrinkage facilitated margin-negative resection while preserving toe function, and a 98% necrosis rate predicts favorable prognosis. Vigilant, long-term surveillance remains essential because ES can relapse late.

Ewing sarcoma of the great toe is exceptionally rare but can be successfully treated when identified early and managed with coordinated multimodal therapy. Clinicians should maintain vigilance for malignancy in non-healing digital lesions to ensure timely intervention and durable outcomes.