The abscopal effect is a phenomenon which refers to disappearance of primary solid tumors following radiotherapy applied to their distant metastatic lesions. There are very few documented cases of this unusual clinical situation and are extremely rarely seen in non-small cell lung carcinomas. A 68-year-old male patient was admitted to our outpatient clinic with dyspnea. Thoracic computed tomography revealed a 12 mm ground-glass opacity lesion with a nodular component located at the superior segment of the lower lobe of the right lung. The lesion had an increased fluorodeoxyglucose uptake on positron emission tomography-computed tomography (SUVmax: 7.2). Transthoracic fine needle aspiration revealed nonsmall cell lung carcinoma. There was no mediastinal lymph node metastasis by cervical mediastinoscopy. Cranial magnetic resonance imaging showed a metastatic nodule in the pons. The patient initially received cranial radiotherapy. The surveillance positron emission tomography-computed tomography revealed the disappearance of the lesion located in the right lung parenchyma without a fluorodeoxyglucose uptake. The patient was scheduled for surgery; however, he refused to have any treatment and was put in follow-up. After six months of the initial diagnosis, repeated positron emission tomography-computed tomography revealed re-appearance of the lesion on the same area measured as 10 mm with a slightly increased fluorodeoxyglucose uptake (SUVmax: 2.4). The patient, then, underwent superior segmentectomy of the right lower lobe and lymph node dissection through video-assisted thoracoscopic surgery. The pathological examination result was reported as an adenocarcinoma with a predominant lepidic pattern. He remained recurrence-free during a 25-month follow-up.

Keywords : Abscopal effect; immune system; non-small cell lung carcinoma; radiotherapy