Case Report: Adult proximal humeral aneurysmal bone cyst: radical resection and reconstruction with osteoconductive allograft & reverse arthroplasty—Ecuador's first reported case and functional outcomes

This case demonstrates the efficacy of aggressive, single-stage reconstruction in adult ABCs, combining advanced orthopedic and oncologic principles. It advocates for molecular diagnostics to confirm primary lesions and supports hybrid graft-prosthesis strategies to optimize outcomes. The success of this approach provides a framework for managing rare, large ABCs in adults, encouraging further exploration of tailored surgical innovations in orthopedic oncology.