Memorial Sloan Kettering medical oncologist and hematologist Matthew Matasar specializes in caring for people with Hodgkin lymphoma and non-Hodgkin lymphoma. His research is focused on finding new and better ways to treat lymphoma, specifically high-risk aggressive lymphomas and certain uncommon types of non-Hodgkin lymphoma. He is Medical Director at MSK Bergen, in New Jersey. For general information, call Memorial Sloan Kettering at 212-639-2000, 24 hours a day, seven days a week. To make an appointment, call us at 800-525-2225, Monday through Friday between 8:30 AM and 5:30 PM ET.