Precise diagnosis and management of non-traumatic radial nerve palsy attributed to multiple rare etiologies: case study and literature review.

While non-traumatic radial nerve palsy is relatively rare, cases triggered by a single etiological factor pose minimal diagnostic and therapeutic challenges. However, for radial nerve palsy driven by multiple factors, the overlapping or masking effects of symptoms and signs from distinct etiologies complicate accurate diagnosis and optimal management. This complexity is further amplified when all contributing factors are rare, presenting a more formidable challenge to precise diagnosis and treatment selection. We present a case of radial nerve palsy attributed to multiple etiological factors, which is notable for the coexistence of three distinct and rare pathogenic entities: elbow joint cyst, hourglass-like constriction, and a specific iatrogenic injury-a combination that is rarely, if ever, documented in the existing literature. Through the synthesis of clinical experience from the diagnostic and therapeutic process and a comprehensive literature review, it aims to provide valuable references for the precise diagnosis and management of such rare clinical entities.