Occult colon cancer in a patient with an unexplained episode of pulmonary embolism

The association between venous thromboembolism and cancer has been widely documented and the main factor responsible for cancer-induced venous thromboembolism is considered mostly linked to a hypercoagulation state induced by the cancer itself. There is no consensus on investigative strategies for occult cancer in a patient with a thrombophilic condition. We report a patient who manifested an isolated episode of pulmonary embolism without specific evident sources of venous thromboembolism. The routine clinical and laboratory work-up to detect an occult cancer did not reveal any malignancy. A history of duodenal ulcer in association with a recent slight alteration in bowel habits led us to perform an esophagogastroduodenoscopy which was negative for malignancy, and a barium enema followed by colonoscopy, which revealed the presence of a tumor limited to the large intestine. An unexplained clinically evident hypercoagulation state, even in the presence of mild clinical symptoms, needs more thorough diagnostic strategies when simple methods of screening for occult cancer are negative.