Pembrolizumab monotherapy in a patient with underlying p-ANCA vasculitis describes the stability of this patient’s malignancy as well as the stability of her underlying autoimmune vasculitis while on pembrolizumab therapy. (a) displays computerized tomography (CT) images at baseline and on-treatment after 3 cycles of pembrolizumab. The size of the vaginal apex mass and lung nodules remained relatively unchanged. Repeat CT scan of the chest, abdomen, and pelvis revealed a pulmonary nodule (1.0 cm), an enlarged perihilar lymph node (1.4 cm), and a right-sided vaginal apex mass (2.8 cm) causing right-sided hydronephrosis (a). (b) CA-125 tumor marker levels are shown. (c) Serum creatinine level over time (black circles, left axis) and ANCA levels (red squares, right axis) are shown. Time on pembrolizumab is highlighted.