Ulcer-forming colon cancer can develop cavity-forming metastatic lung tumors.

A 67-year-old man with abdominal pain and vomiting was referred to our hospital for the treatment of ileus. Enhanced computed tomography (CT) showed marked dilatation of the ileum and a presumed cecal tumor. After the intestinal decompression using nasogastric tube, a colonoscopy showed a type 3 tumor in the cecum. Endoscopic biopsy pathologically showed atypical cells growing in a cribriform fashion, leading to the diagnosis of cecal cancer. Staging CT showed multiple lung nodules either in a solid or a cavity-forming fashion and a presumed peritoneal disseminating lesion. Smaller lung nodules tended to show a solid pattern and larger ones a cavity-forming pattern. On diagnostic laparoscopic operation, a frozen section of the resected peritoneal lesion proved peritoneal dissemination. The patient, therefore, underwent palliative colectomy with functional anastomosis followed by thoracoscopic resection of one cavity-forming lung nodule for the accurate evaluation of the disease spread. Pathologic study showed marked tumor tip deciduation of cecal cancer and interminglement of necrotic tissue and exfoliated cancer cell clusters in the cavity of the metastatic lung tumor. Oncologists should note that ulcer-forming colon cancer can develop metastatic lung tumors in a cavity-forming fashion. Co-presence of small solid nodules and large cavity-forming ones suggests metastatic lung tumors from ulcer-forming colon cancer.