Spectrum of Cystic Mediastinal Lesions: An Imaging Review

Cystic and cyst-like lesions of the mediastinum encompass a broad spectrum of entities ranging from benign congenital abnormalities to inflammatory or malignant processes with cystic components. These lesions are frequently encountered with cross-sectional imaging and may present a diagnostic challenge due to overlapping imaging appearances. Accurate characterization is critical, as misclassification can lead to unnecessary surgical intervention or delayed diagnosis of clinically significant disease. These lesions can be incidentally identified on routine chest radiographs as paramediastinal opacities. CT is typically the initial imaging modality for further evaluation of mediastinal lesions and provides essential information regarding lesion location, morphology, and relationship to adjacent structures. MRI offers superior soft-tissue characterization and plays a key role in problem-solving, particularly when CT findings are indeterminate. The use of T1- and T2-weighted sequences, along with diffusion-weighted imaging, facilitates differentiation of simple cysts from lesions containing solid, proteinaceous, or malignant components. Awareness of characteristic imaging features of common congenital cysts, acquired cystic lesions, and important mimics further improves diagnostic confidence. In conclusion, mediastinal cystic lesions require a structured imaging-based approach for accurate diagnosis. Integration of clinical context, anatomic location, and multimodality imaging findings, with particular emphasis on MRI, supports appropriate risk stratification and individualized patient management.