Lung squamous cell carcinoma with metastases in the left atrium and left ventricle responds to treatment with immunotherapy:  A case report

Tumor metastasis is a phenomenon in which tumor cells grow in distant organs far from their primary site and is the final and most lethal manifestation of cancer. Most patients with cancer succumb to metastatic disease, not primary tumors. The occurrence of cardiac metastases is rare, but any primary tumor can potentially metastasize to the heart. The present report describes a 71-year-old male with stage IV lung squamous cell carcinoma who was diagnosed with cardiac metastases. These were identified as pedicled structures in the left atrium and left ventricle via echocardiography and positron emission tomography/computed tomography (PET/CT) prior to curative therapy. PET/CT imaging confirmed increased uptake of the tracer in these regions, indicating malignancy. Given the high expression of programmed cell death-ligand 1, the patient was treated with sintilimab immunotherapy. Despite a transient increase in liver function markers during treatment, the patient completed eight cycles of immunotherapy. Notably, both the primary lung tumor and cardiac metastases were markedly reduced in size, indicating a positive therapeutic response. The present case underscores the potential efficacy of immunotherapy in the management of cardiac metastases originating from lung cancer.