Generalized Lymphatic Anomaly (GLA) is a rare multisystem congenital disorder originating from the abnormal development of the lymphatic system which occur under the spectrum of Complex Lymphatic Anomaly (CLA). In addition to GLA, other CLAs include Kaposiform Lymphatic Anomaly (KLA) and Gorham-Stout Disease (GSD). Lymphatic malformations (LM) associated with GLA are usually apparent at birth or by two years of age. GLA can affect almost any organ of the body but is most commonly associated with lymphatic abnormalities in the skin, abdominal/thoracic viscera and bone. Multisite soft tissue LM can occur in all CLAs, with macrocystic lymphatic malformations being most common in GLA. These lesions can be found in the mediastinum, retroperitoneum, and subcutaneous tissue. Abdominal viscera involved include the spleen and liver. The frequency of focal splenic lesions is higher with GLA and KLA in comparison to GSD. On MRI, the lesions exhibit marked T2 hyperintensity with no discernable enhancement. In patients with larger splenic lesions, areas of T1 hyperintensity have been documented. Liver lesions in GLA have a similar appearance to the previously described splenic lesions. Nakamura et al. found that more than 30 focal splenic lesions and/or focal splenic lesions with maximum diameters greater than >10 mm were observed only in patients with GLA. On contrast enhanced CT, the lesions are generally well-circumscribed and hypodense. Within the thorax, mediastinal LMs can be seen in GLA but are more common in KLA and GSD. Chylous effusions can occur in all of the CLAs, although it has been reported that effusions in GLA were more likely to be associated with mediastinal involvement. Osseus involvement is common in patients with GLA. GLA has a predilection for the appendicular skeleton, in which the ribs are most affected although cranial, vertebral and lower extremity lesions have been reported. The lesions are usually non-contiguous with medullary destruction and sparing of the cortex. This is in contrast to GSD where cortical destruction, progressive osteolysis, contiguous lesions, and soft tissue infiltration are more common. Educational Goals: 1) Illustrate the most common imaging characteristics by each organ system affected by GLA and how to differentiate GLA from other CLAs. 2) Raise awareness of the optimal imaging evaluation in patients with GLA. 3) Outline an approach to multidisciplinary management of patients with GLA through a vascular anomalies center.
SPR 2023 Annual Meeting & Postgraduate Course
Generalized Lymphatic Anomaly,
Complex Lymphatic Anomaly