Current Perspectives on Pectoralis Minor Syndrome: A Narrative Review

Thoracic outlet syndrome (TOS) encompasses a group of disorders caused by compression of the brachial plexus or subclavian vessels as they pass from the neck to the upper limb. Among its variants, pectoralis minor syndrome (PMS) is increasingly recognized as a distinct cause of neurovascular compression beneath the pectoralis minor muscle. PMS typically presents with anterior chest wall pain, paresthesia, weakness, or upper-limb swelling, closely resembling neurogenic or vascular TOS. Diagnosis relies on detailed history and physical examination, with ultrasound-guided pectoralis minor block serving as a key confirmatory and prognostic test. At the same time, dynamic ultrasonography or venography provides supportive evidence when vascular involvement is suspected. Most patients respond to conservative management, which includes posture correction, stretching of the pectoralis minor, physical therapy, and botulinum toxin injection. In contrast, refractory cases benefit from surgical pectoralis minor tenotomy, which offers durable symptom relief with minimal complications. Early recognition and precise localization of compression are essential to guide effective treatment and prevent unnecessary thoracic outlet procedures. This study provides a comprehensive review of PMS, detailing its etiologies, clinical features, diagnostic strategies, differential diagnoses, and treatment options to improve recognition and optimize management of this underdiagnosed condition.