NCI Definition: A malignant neoplasm arising from the endothelial cells of the lymphatic vessels. 
There is 1 clinical trial for lymphangiosarcoma, of which 1 is open and 0 are completed or closed. Of the trial that contains lymphangiosarcoma as an inclusion criterion, 1 is phase 2 (1 open).
Pembrolizumab is the most common intervention in lymphangiosarcoma clinical trials.
2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 6. This dataset does not represent the totality of the genetic landscape; see paper for more information.