A Boy with Abdominal Cramping

Posted by • February 26th, 2016

2-25-2016 9-20-49 AMColorectal carcinoma is extremely uncommon in children. Hereditary cancer syndromes may confer a predisposition to colorectal carcinoma in children.

A 10-year-old boy was seen in the gastroenterology clinic because of abdominal cramping and fevers. Abdominal imaging studies revealed circumferential thickening of a segment of the colonic wall and mesenteric lymphadenopathy. A diagnostic procedure was performed. A new Case Record of the Massachusetts General Hospital summarizes.

Clinical Pearl

• What is the colorectal cancer risk associated with the familial adenomatous polyposis syndrome?

The familial adenomatous polyposis syndrome is caused by a germline mutation of the adenomatous polyposis coli (APC) gene on chromosome 5 and is associated with numerous adenomatous polyps of the colon and intestine. The risk of colon adenocarcinoma among patients with the familial adenomatous polyposis syndrome approaches 90% by the time they are 50 years of age, and adenocarcinoma has been reported in affected children.

Clinical Pearl

• What is the Lynch syndrome?

The Lynch syndrome (hereditary nonpolyposis colorectal cancer), which accounts for 3% of colorectal cancers in adults, is associated with a germline mutation in a DNA mismatch-repair gene. Patients with the Lynch syndrome often have a strong family history of cancers that occur at an early age, even during childhood or adolescence.

Morning Report Questions

Q: What is the constitutional mismatch-repair deficiency (CMMRD) syndrome?

A: Patients who have inherited two mutations of DNA mismatch-repair genes are known to have the constitutional mismatch-repair deficiency (CMMRD) syndrome. The majority of cases of the Lynch syndrome are attributable to a germline mutation in either MSH2 or MLH1; only approximately 10% of cases are associated with PMS2 mutations. In contrast, more than half the patients with the CMMRD syndrome carry biallelic mutations in PMS2.

Q: What types of cancer are associated with the Lynch syndrome and the CMMRD syndrome?

A: As compared with the Lynch syndrome, which is classically associated with a high risk of the development of colorectal and endometrial cancer in adulthood, the CMMRD syndrome (which was first described in 1999 as a pediatric cancer-susceptibility syndrome) is associated with a different spectrum of tumors and age range at onset. In the largest reported series, which included 146 cases, cancers of the central nervous system arose in 81 patients (55%) at a median age of 9 years, colorectal cancers in 59 patients (40%) at a median age of 16 years, and hematologic cancers in 48 patients (33%) at a median age of 6 years. More than 60% of patients with the CMMRD syndrome have café au lait macules similar to those associated with neurofibromatosis type 1, and approximately one third of affected patients have multiple colonic adenomas.

One Response to “A Boy with Abdominal Cramping”

  1. dr premraj pushpakaran says:

    genetic predisposition of Lynch syndrome is known and the female patient with mutation in any of these genes pose a risk of bearing endometrial cancer in adulthood.
    Great work form MGH.