Mark M. Souweidane, M.D.
Dr. Mark M. Souweidane, vice chair of the Department of Neurological Surgery at Weill Cornell Medicine and director of pediatric neurological surgery at NewYork-Presbyterian Komansky Children’s Hospital of Children’s Hospital of New York, has achieved a new milestone, completing more than 300 endoscopic resections of colloid cysts – a minimally invasive procedure to remove benign pockets of tissue in the brain. This accomplishment reflects decades of experience in minimally invasive, endoscopic neurosurgery and a career-long commitment to redefining the best surgical management for these rare brain lesions.
Colloid cysts are developmental, benign growths that develop in the third ventricle of the brain, the deepest and most central part of the brain. They contain a thick colloid substance and can obstruct the flow of cerebrospinal fluid as they grow. This blockage can cause headaches, changes in vision, cognitive/memory complaints, and rarely, sudden death. NewYork-Presbyterian and Weill Cornell Medicine offer a rare comprehensive team that includes specific colloid cyst neuroimaging protocols and neuropsychological testing.
Endoscopic removal uses a narrow endoscope, approximately the size of a standard pencil, to access and remove the cyst. This approach results in a smoother and more rapid recovery. The procedure is among the least invasive ways to treat a colloid cyst and has become an important option for patients who need surgical intervention.
“Every one of these procedures represents a patient who trusted our team at a vulnerable moment,” Dr. Souweidane said. “That trust is something I never take lightly.”
He added, “When I first began performing these operations, the goal was to make treatment safer and less disruptive. Over time, experience taught us how to refine each step. Reaching 300 cases demonstrates how consistency and careful attention to detail can advance care. Critically, since colloid cysts are rare (1/1,000,000), this unparalleled experience provides me unique insights for specific patients’ needs, empowering a nuanced and personalized approach.”
Weill Cornell Medicine also maintains a colloid cyst patient registry to ensure continued improvements in technique and outcomes. This registry supports research on cyst behavior, outcomes and long-term patterns, which helps guide treatment planning for current and future patients.
“The registry has been invaluable,” Dr. Souweidane said. “It gives us the information we need to understand which patients may need surgery and how to support them before and after treatment. It has strengthened our ability to make informed, thoughtful decisions. The massive amount of data has also defined different types of colloid cyst rather than approaching all as a ‘one-size-fits-all.”
Patients who undergo surgery generally have excellent outcomes when treated by experienced neurosurgical and clinical teams with familiarity with colloid cysts. Dr. Souweidane’s experience and volume of endoscopic surgeries to remove colloid cysts in children and adults makes him one of the world’s experts in this minimally invasive procedure.
To learn more about colloid cysts and treatment options at Weill Cornell Medicine, visit: https://neurosurgery.weillcornell.org/condition/colloid-cysts