Mesenteric Plexiform Neurofibroma as a Cause of Weight Loss and Chronic Diarrhea in a Patient with YPEL3 Variant

Abstract

Mesenteric plexiform neurofibroma is a subtype of plexiform neurofibroma that involves the mesentery and causes a variety of gastrointestinal complaints. Plexiform neurofibroma is classically found in patients with neurofibromatosis type 1, although genetic contributions to plexiform neurofibroma pathogenesis are heterogeneous. We report the first case of mesenteric plexiform neurofibroma in a patient with a YPEL3 pathogenic variant. This patient presented with growth failure, generalized abdominal pain and chronic diarrhea. She was confirmed to have mesenteric plexiform neurofibroma on histopathology and targeted sequencing on affected tissue confirmed that there were no neurofibromatosis type 1 variants present. Given that this patient's mesenteric plexiform neurofibroma is associated with YPEL3 dysfunction, she is unlikely to benefit from MEK inhibitors, which are the newly approved treatment for inoperable plexiform neurofibroma in patients with neurofibromatosis type 1.

A case report of mesenteric involvement in neurofibromatosis type 1

“…About 10-25% of NF-1 individuals are said to experience abdominal involvement. [ 4 - 6 ] In the abdomen, lesions typically develop in the paraspinal region as well as the retroperitoneal space. [ 4 ] Mesenteric fibromatosis is a very uncommon NF-1 manifestation.…”

“…[ 8 , 9 ] On the venous phase CT scans, the lesions exhibit a modest amplification, ranging from 30 to 50HU. [ 1 , 2 , 4 , 6 ] Due to the mucinous stroma of tumors that may be seen under a microscope, neurofibromas exhibit poor attenuation. [ 1 , 3 ] Lesions in the perirectal area frequently show up as perirectal fatty infiltration and can spread to other pelvic tissues like the vagina or uterus.…”

“…[ 5 ] Thus, early detection is essential before the tumor grows too big to be effectively treated for mesenteric neurofibromatosis. [ 4 - 6 ]…”