The teenage girl reported decreased appetite, increased bowel movements – up to 7 times a day – blood in her stools, and dramatic weight loss – 30 pounds over 4 months. Her pediatrician diagnosed anemia and prescribed iron supplements. Then she began to experience abdominal pain that worsened with each bowel movement, and she was referred to Hopkins Children’s. There a CT exam showed a well-defined mass on the tail of her pancreas, as well as a swollen rectum.
“We began to think of inflammatory bowel disease [IBD] with a secondary finding of a pancreatic mass, perhaps an epithelial pancreatic tumor of low malignancy potential,” pediatric resident Breanna Barger-Kamate reported at a recent Hopkins Children’s case conference.
Gastroenterology, Oncology and Surgery were brought into the case, and everyone agreed the pancreatic mass had to come out – even tumors with low malignancy potential have some malignant potential. Other issues were not so clear. Was the pancreatic mass and swollen bowel one diagnosis or two? What was the pancreatic mass, and was it related to the GI symptoms – perhaps an adenoma with metastasis, a GI lymphoma, a neuroendocrine tumor secreting something stimulating the GI symptoms? The differential was expanding.
The answers came as the team set out to determine what type of IBD they were dealing with – Crohn’s or ulcerative colitis. That way they could get it under control so this anemic and thin patient could recover well from surgery. An upper endoscopy showed H. pylori gastritis, but a lower endoscopy was not possible because of the extent of rectal swelling. So an MRI with contrast was ordered to show possible small bowel lesions characteristic of Crohn’s. But the findings pointed to something surprisingly different and more ominous – colorectal carcinoma (CRC) – something not typically on the top of the differential list in pediatric cases.
“You just don’t think about colorectal disease in a child because it’s so rare, about one case in 1 million children,” said pediatric oncologist Matteo Trucco. “So, in children it’s usually more advanced at diagnosis. Patients may have symptoms for several months before the disease is identified.”
That makes paying attention to family history, as well as symptoms like rectal bleeding, even more important, said Trucco, noting that colorectal cancer in children is often related to a colorectal family cancer syndrome like Familial Adenomatous Polyposis (FAP) or Hereditary Nonpolyposis Colorectal Cancer (HNPCC). “With colorectal cancer in the young patient, you have to think there’s a syndrome involved,” said Trucco, citing some 800 mutations in the APC gene associated with FAP.
If a family member has such a genetic mutation, added pediatric gastroenterologist fellow Doug Mogul, other family members need to be tested genetically. If a patient has a family history of a syndrome like FAP but a mutation is not identified, he added, “you can screen a child endoscopically around 13 years of age.”
So, was there a link between the mass on the pancreas, which histology confirmed as a solid-pseudopapillary tumor, or SPT, and the colorectal carcinoma? Pathology and Genetics, Barger-Kamate said, are working on it. Fortunately, added Trucco, SPTs tend to have low potential for malignancy and, once removed, leave most patients disease free. Colorectal carcinomas in children, on the other hand, are trickier to deal with. More than 50 percent of CRC in children – compared to 15 percent in adults – are mucinous adenocarcinomas, meaning they contain mucus that some theorize allows cells to spread faster than cells in regular adenocarcinomas. The plan for this patient is chemotherapy and radiation therapy to shrink the tumor before excision. The take-home message in this case?
“With a chronic condition like Crohn’s her weight loss might have been more gradual, but she had a really drastic drop in her growth curve,” said Barger-Kamate. “So the take-home was always keep the differential broad when things don’t add up.”