Dr. Jonathan S. Treisman

Timothy Wassenaar is a Hematologist Oncology specialist and a Hematologist in Oconomowoc, Wisconsin. Dr. Wassenaar is rated as a Distinguished provider by MediFind in the treatment of Antiphospholipid Syndrome. His top areas of expertise are Chronic Lymphocytic Leukemia (CLL), Follicular Lymphoma, Adult Immune Thrombocytopenia, Chronic B-Cell Leukemia (CBCL), and Bone Marrow Aspiration. Dr. Wassenaar is currently accepting new patients.

“I am committed to providing the highest standards of care in the fields of oncology and hematology. Because each cancer patient is unique, I strive to incorporate their objectives and preferences to their individualized treatment plan. I am grateful to each of my patients for allowing me and my care team at Northwest Oncology & Hematology the opportunity to guide them through treatment decisions and for placing their trust in us.”. Dr. Barraza is rated as an Advanced provider by MediFind in the treatment of Antiphospholipid Syndrome. His top areas of expertise are Pleuropulmonary Blastoma, Paget Disease of the Breast, Breast Cancer, and Posterior Fossa Tumor.

“In combining cutting-edge medical practice with a team-based approach, it is my passion to treat cancers and blood disorders. I feel privileged to help my patients and their families navigate this difficult time in their lives, and I feel inspired by their strength and grace. Ultimately, my goal is to deliver to my patients the best care available within a supportive environment.”. Dr. Messinger is rated as a Distinguished provider by MediFind in the treatment of Antiphospholipid Syndrome. Her top areas of expertise are Paget Disease of the Breast, Lung Cancer, Pleuropulmonary Blastoma, Breast Cancer, and Bone Marrow Aspiration.