A narrative review of Poland's syndrome: theories of its genesis, evolution and its diagnosis and treatment.

Poland's syndrome (PS) is a rare musculoskeletal congenital anomaly with a wide spectrum of presentations. It is typically characterized by hypoplasia or aplasia of pectoral muscles, mammary hypoplasia and variably associated ipsilateral limb anomalies. Limb defects can vary in severity, ranging from syndactyly to phocomelia. Most cases are sporadic but familial cases with intrafamilial variability have been reported. Several theories have been proposed regarding the genesis of PS. Vascular disruption theory, "the subclavian artery supply disruption sequence" (SASDS) remains the most accepted pathogenic mechanism. Clinical presentations can vary in severity from syndactyly to phocomelia in the limbs and in the thorax, rib defects to severe chest wall anomalies with impaired lung function. Most patients have subtle presentation at birth and milder forms in childhood. Functional limitations due to PS are usually minimal. Surgical treatment aims to improve pulmonary functions arising from severe thoracic deformities but is more often done to enhance the cosmesis. The use of adipose-derived mesenchymal stem cells and fat transfer have shown promising results in recent times for correction of chest defects and breast augmentation. Gaining deeper insights into the etiopathogenesis and clinical presentation of PS will improve the clinical recognition and management of this rare condition. In this review article, we aim to outline the details of this syndrome including its etiopathogenesis, evolution, spectrum of clinical manifestations, other systemic associations, diagnostic modalities, and recent advances in treatment.