A 57-year-old male was diagnosed with sigmoid colorectal cancer [stage IIA (T3N0M0), KRAS mutation-positive, G12D] and underwent anterior resectio...A computed tomography (CT) scan of the chest revealed several large masses in the lungs (longest diameter, 36 mm; Fig. 1A–C) and the patient commenced regorafenib 160 mg/day....In the present study, we report the case of a patient with a characteristic manifestation of multiple pulmonary metastases of colorectal cancer that responded to regorafenib with cavity formation.