A one-in-a-million diagnosis

Earlier that summer, Endres was feeling increasingly unwell. He had a lot of pain in his abdomen and was having a difficult time keeping food down. His primary doctor referred him to a specialist to determine the cause of his worsening symptoms.

A biopsy confirmed the then-28-year-old Endres had an inflammatory myofibroblastic tumor that had spread throughout his abdomen.

“It grew around a bunch of organs, and they didn’t know what the outcome would be for me,” Endres said.

Inflammatory myofibroblastic tumors can form in mesentery tissue, which connects the organs of your abdomen, as well as in mucosal tissue. These tumors are very rare—the National Cancer Institute states it only occurs in less than 1 in a million people. They also generally only affect children and young adults.

Endres began treatment through the UW Carbone Cancer Center. First, he took an oral chemotherapy medication in the morning and at night and had quarterly scans to monitor that progress.

“I started feeling better and I could keep food down,” he said.

However, in May 2021 he began having abdominal pains again. At that time, Endres’ team decided to pursue surgery to remove the tumor.

Dr. Daniel Abbott, associate professor in the Division of Surgical Oncology and Surgical Director for UW Health Liver and Pancreas Center, performed the operation on Endres.

“What made him a surgical candidate is that he responded really, really well to chemotherapy,” Abbott said. “It didn’t spread to the organs outside of his abdomen, so he’s very fortunate that he responded so well to chemotherapy.”

Because inflammatory myofibroblastic tumors are so rare, Endres was the first patient Abbott had operated on with that type of tumor. Abbott prepared by reviewing literature and case studies as well as reaching out to colleagues.

Endres’ operation involved taking out his gallbladder and parts of his colon, liver, and lining of his abdominal cavity. Abbott said the procedure lasted about four to five hours.

Endres continues to see his oncologist, Dr. Howard Bailey, to monitor for any new tumor growth. At this point, there is no evidence of the tumor within Endres’ abdomen, but he continues to take an oral chemotherapy medication.

“I’m feeling great,” Endres said. “I’m really thankful.”

Bailey, who is also director of UW Carbone, specializes in treating soft tissue tumors. Like Abbott, he sought out existing literature and commentary by peers who have treated that tumor or similar illnesses to determine the best plan for Endres.

“It’s anecdotal,” he said. “Everybody puts together their experiences, what they did, and you try to draw some conclusions from that.”

Abbott said it’s likely Endres’ tumor will return, based on what’s known about inflammatory myofibroblastic tumors. That’s why regular surveillance is important.

“Hopefully it will be way down the road and it will be minimal,” Abbott said. “Howard and I will work closely, and if he thinks something has returned we can look at surgery again.”