55 yr old non smoker presents with GI bleeding and crampy abdominal pain. Physical exam is unremarkable. Colonoscopy is performed and reveals a 5 cm circumferential mass in the rectum, just distal to the peritoneal reflection.
Biopsies at colonoscopy reveal moderately differentiated adenocarcinoma.
Additional work up including CT of the chest, abdomen, and pelvis reveals no abnormalities other than a non clacified lesion in the lower left lobe of the lung measuring 1.8 cm and the rectal lesion. PET/CT of the body is unremarkable aside from uptake in the lower left lung and proximal rectum. There are no other sites of regional lymph node uptake or metastatic disease.
Biopsy of the lung lesion is positive for adenocarcinoma. Immunohistochemical stains reveal CK 7 (-), CK 10 (+), TTF -1 (-).