Histologic changes can be involved in resistance to anticancer drugs. Transformation to small cell lung carcinoma (SCLC) following treatment with EGFR tyrosine kinase inhibitors has been reported in patients with EGFR-mutant lung adenocarcinoma. Herein, we report a case of ALK-rearranged lung adenocarcinoma with SCLC-like histology in a metastatic abdominal nodule that was resistant to crizotinib therapy.