Pseudoprogression of lung cancer after concomitant chemoradiotherapy.

We observed re-enlargement of a squamous cell carcinoma without recurrence. The tumour regressed markedly after concomitant chemoradiotherapy, but within 1 month, we supposed that the tumour had enlarged again and resection was performed. The resected tissue showed evidence of haemorrhage and several lymphocytes and macrophages, but no malignant cells were detected. We herein report a rare case of lung cancer showing a pathological complete response despite re-enlargement of tumour lesion.