[A case of rectal cancer with interstitial pneumonia successfully treated with preoperative radiation therapy]

We report here a case of rectal cancer with interstitial pneumonia was successfully treated with preoperative radiation therapy. An 81-year-old man with complaints of constipation and melena was admitted to our hospital for the purpose of close inspection and medical treatment. In colonoscopic examination, we found a type-3 9 cm tumor in mainly occupied lower rectum (Rb), which developed all circumference-related stenosis. We diagnosed the tumor as Group V (adenocarcinoma) in biopsy. In abdominal computed tomography (CT) scan, the rectal tumor was directly invaded to the prostate and left internal obturator muscle. We diagnosed it to be cStage II rectal cancer (Rb) from various image findings. In addition, chest CT showed interstitial pneumonia. At first therapy, we did not perform pelvic evisceration nor chemotherapy because the patient was aged having interstitial pneumonia. We performed loop colostomy and preoperative radiation therapy (total 50 Gy). After the radiation therapy, there was a notable reduction in tumor, and a direct invasion to the prostate and left internal obturator muscle was not identified upon imaging. After the one year course of radiotherapy, we performed Mile's operation. After the operation, we did not perform adjuvant chemotherapy, but there has been no recurrence observed.