Endoscopic Resection of a Giant Pedunculated Leiomyoma in the Sigmoid Colon: A Case Report

Inside the human body, the digestive tract is a long, muscular tube designed to move food along. Occasionally, the wall of this tube can develop a growth. Most of the time, these growths are polyps, which are common and often easy to remove. However, a different kind of growth can form from the smooth muscle layer itself, known as a leiomyoma. These are benign, meaning they are not cancer, but they are rare in the colon, making up only a tiny fraction of all such tumors found in the digestive system. When these tumors grow large, they can block the passage of waste, causing pain or difficulty with bowel movements. For decades, the standard way to remove a large tumor from the colon was through open surgery, which involves cutting into the abdomen to take out the growth. This is a major procedure with a long recovery time. The question facing doctors has been whether a less invasive approach, using a flexible camera passed down the throat and into the colon, could safely remove even the largest of these rare muscle tumors without needing to cut the patient open.

A team of doctors at The First People's Hospital of Liangshan Yi Autonomous Prefecture in China recently answered this question with a remarkable case. They treated a 54-year-old man who had been struggling to pass stool for over a year. When doctors looked inside his colon with a camera, they found a massive, mushroom-shaped tumor in the lower part of the large intestine, known as the sigmoid colon. The growth was enormous, measuring 6 centimeters by 5 centimeters at its head, with a thick stalk that was 3 centimeters long and 2 centimeters wide. The surface of the tumor was red and inflamed, with a sore at the very tip caused by friction against the inside of the bowel. Because the tumor was so large and sitting in a narrow part of the intestine, it had created a significant blockage. A biopsy, which is a small sample taken to check for cancer, showed only inflammation and scar tissue, but because the sample was small, the doctors could not be completely sure it was not something more serious. The patient, however, was very worried about the idea of major surgery and asked if there was another way.

The medical team decided to attempt a procedure called endoscopic submucosal dissection. This technique allows doctors to peel a tumor off the inner wall of the colon from the inside, using a specialized knife passed through the camera. It is a delicate task, especially with a tumor this size, because the doctors must cut around the base without damaging the deeper muscle layers of the colon wall, which could cause a hole or perforation. To prepare, they injected a mixture of fluid under the tumor to lift it up and create a safe cushion between the growth and the deep muscle. Using a high-frequency electric knife, they carefully cut a circle around the base of the tumor's stalk. They then worked their way down the stalk, separating the tumor from the colon wall. The doctors relied on the natural weight of the tumor to help pull it away as they cut, rather than using extra tools to hold it. The entire growth, including its thick stalk, was removed in one piece. The doctors then closed the remaining opening in the colon wall with small metal clips, much like using staples to close a wound. The procedure was successful, and the patient was able to leave the hospital just two days later.

When the removed tissue was examined under a microscope, the diagnosis was confirmed. The cells were smooth muscle cells, and specific chemical tests showed they reacted to markers for smooth muscle but did not react to markers for other types of tumors, such as gastrointestinal stromal tumors or cancer. This proved the growth was indeed a leiomyoma. The patient had no complications and returned to normal life, with follow-up checks at three and six months showing no signs of the tumor returning. This case is significant because it shows that even a very large, pedunculated tumor in the colon can be removed safely using only a camera and a knife, avoiding the need for open surgery. While surgery has traditionally been the go-to for tumors larger than 5 centimeters, this successful removal suggests that for tumors with a long stalk and no signs of deep invasion, a minimally invasive approach is a viable option. It offers a path to cure that preserves the organ and allows for a much faster recovery, providing hope for other patients facing similar rare and difficult diagnoses.