Herein, we report a case of dedifferentiated liposarcoma (DDLPS) arising from the chest wall with spontaneous shrinkage, which revealed remarkable tumor infiltration of CD8+ lymphocytes and a 90% positive ratio of programmed cell death-ligand 1 (PD-L1), suggesting a spontaneously-induced T cell response. The gene discussed is CD274; the disease is dedifferentiated liposarcoma.