Complex Lymphatic Anomalies: A Comprehensive Review of Imaging Features and Diagnostic Considerations

Within the overarching diagnosis of lymphatic anomalies, the subgroup of complex lymphatic anomalies (CLAs) has classically been comprised of 4 entities which are characterized by multisystem involvement, structural complexity, and functional impairment of the lymphatic system. The 4 subtypes generalized lymphatic anomaly, kaposiform lymphangiomatosis, Gorham-Stout disease, and central conducting lymphatic anomaly, share overlapping characteristics which can make differentiating between them a challenge. Recently, a fifth subtype, generalized lymphatic dysplasia, has been defined as a separate classification. CLAs may contribute to significant morbidity for affected patients, and a multidisciplinary approach is critical to optimize treatment approaches. From a diagnostic perspective, it is imperative that readers interpreting those images for patients with CLAs are aware of various manifestations of the different subtypes, and that the readers have a strong understanding of follow-up imaging recommendations when needed. In conjunction, the utility of images to guide intervention continues to grow, and maintaining an updated perspective on the diagnostician's role is critical to facilitating excellent patient care. We aim to provide an overview of current practices and approaches to further the readers' knowledge base on CLAs.