CEA test: Carcinoembryonic antigen test is to detect response to therapy in cancer patients, especially colon cancer, with normal range of less than 2.5 (less than 5 in heavy smokers). Note that a positive test may not always be indicative of cancer.
Os Trigonum Syndrome. An Os Trigonum is a small, extra bone found at the back of the ankle in approximately 5-10% of people. Often it goes completely unnoticed, not causing any problems.
Because the symptoms of os trigonum can mimic other common foot and ankle injuries like Achilles tendon injuries, sprains and even fractures, a careful physical exam followed by x-rays or other imaging tests are commonly used to confirm diagnosis prior to treatment.