Biopsy of the acetabular soft tissue mass showed hypofractionated adenocarcinoma, and positron emission tomography–CT showed partial pathological remission after 3 months of therapy with PD-1 inhibitors; progression was noted at review after 5 months of treatment, and the patient’s CT scan indicated complete pathological remission within 6 months during PD-L1 inhibitor replacement. The gene discussed is PDCD1; the disease is adenocarcinoma.