Small cell carcinoma (SCC) is derived from neuroendocrine cells primarily found in the lung. Extra-pulmonary SCC is relatively rare, comprising <5% of all SCCs. Most extra-pulmonary SCCs are found in the gastrointestinal tract; however, SCC of the rectum is extremely rare. The tumour biology of rectal SCC is similar to that of pulmonary SCC, an aggressive tumour that results in frequent distant...