Vedolizumab as a Potential Culprit in the Development of Ovarian Teratoma?

Vedolizumab is a new humanized monoclonal antibody that has been reserved for those with moderate-to-severe Crohn's disease and ulcerative colitis who have failed immunomodulator and TNF-α antagonist therapy, and for those who have an increased risk for developing progressive multifocal leukoencephalopathy. Because it targets gastrointestinal tract-specific lymphocytes, meta-analyses and integrated studies have shown that vedolizumab causes fewer extraintestinal adverse effects, such as opportunistic infections and malignancies, compared with anti-TNF therapies. We present the case of a patient who developed an ovarian teratoma after initiation of vedolizumab therapy.