Dr. Lyons has served leadership roles with many professional societies, organizations, and institutions, including Bexar County Hospital District, South Texas Regional Blood Bank, Southwest Texas Methodist Hospital, and Humana Hospital of San Antonio.

Currently, Dr. Lyons is the president of Cancer Care Centers of South Texas (CCCST)  and the medical director for the Myelodysplasia Foundation Center of Excellence at CCCST.  Dr. Lyons has served for five years on the editorial board for the publication Blood, as well as serving as an alternate on the Carrier Advisory Counsel for Medicare of Texas.  In addition, Dr. Lyons is a Clinical Professor of Medicine at the University of Texas Health Science Center at San Antonio. 

Dr. Lyons has received the special honor of being listed repeatedly in the Best Doctors in America.

Dr. Lyons is actively involved in clinical research. His special interests in oncology are in hematologic malignancies, such as leukemia, lymphoma, and multiple myeloma. He is also interested in non-malignant hematological disorders such as thrombosis, coagulation, platelet, and vascular disorders. He has published over 33 articles and 49 abstracts in peer-reviewed journals, and has taken a leading role in over 33 research studies.