E1173. Circling The Drain: Pitfalls In Thoracic Imaging Interpretation Related to the Lymphatic System
Authors
Katherine Hartmann;
Hospital of the University of Pennsylvania
Chantal Chahine;
Hospital of the University of Pennsylvania
Maxim Itkin;
Hospital of the University of Pennsylvania
Farouk Dako;
Hospital of the University of Pennsylvania
Background
The thoracic lymphatic system is an intricate network of vessels and lymph nodes that plays a key role in circulating chyle, maintaining intrathoracic fluid balance, and producing and circulating white blood cells and other immune components. Intrathoracic manifestations of disease are predicated on disease pathophysiology as well as the underlying lymphatic pathways and tributaries. As such, anatomic variants can make for a wide range of radiological phenotypes of disease and often lead to diagnostic pitfalls. Understanding thoracic lymphatic drainage patterns is essential to understanding pulmonary manifestations of common disease processes and avoiding pitfalls in thoracic imaging interpretation. The purpose of this work is first to review thoracic lymphatic anatomy and common anatomic variants, and second to conduct a case-based review of thoracic lymphatic anatomy-related diseases and diagnostic pitfalls.
Educational Goals / Teaching Points
By the end of this pictorial exhibit, the participant should understand the normal and variant anatomy of the thoracic lymphatic system with a focus on the drainage pathways of the mediastinum, lungs and pleura, discuss lymphatics-related intrathoracic pathology, and identify pitfalls in thoracic imaging interpretation due to lymphatic variants.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
In this pictorial presentation, we will review the physiology, of normal and variant anatomy of the thoracic lymphatic system with a focus on the drainage pathways of the mediastinum, lungs, and pleura. To this end, we will use graphic illustration, as well as conventional and magnetic resonance lymphangiogram cases. Using a case-based approach of chest radiographs and chest computed tomography with lymphangiographic and thoracic vascular correlates, we will discuss cases in which the radiological appearance of intrathoracic pathology can be correlated with normal, variant, or aberrant lymphatic functional anatomy, and its implications on diagnosis and management. The topics discussed as case examples will include pulmonary edema, intrathoracic lymphoma (and other causes of mediastinal mass effect), thoracic spread of infection, thoracic spread of malignancy, and abnormal lymphatic perfusion.
Conclusion
The functional anatomy of the thoracic lymphatic system underpins disease manifestation in the chest. Radiologists should be familiar with normal anatomy, anatomic variants, and the potential diagnostic pitfalls they can lead to.
