# Unveiling the Rare: A Case Report of Rectal Schwannoma in a Neurofibromatosis Type 1 Patient

## TL;DR

A 28-year-old man with Neurofibromatosis Type 1 had a rare rectal schwannoma discovered through colonoscopy and biopsy.

## Contribution

This case report highlights the rare occurrence of rectal schwannoma in a Neurofibromatosis Type 1 patient.

## Key findings

- A rectal mass was identified in an NF-1 patient and diagnosed as a low-grade schwannoma.
- Schwannomas are rare in the gastrointestinal tract and even rarer in the rectum.
- Schwannoma should be considered in the differential diagnosis for rectal masses in NF-1 patients.

## Abstract

Neurofibromatosis type 1 (NF-1) is an autosomal dominant neurocutaneous disorder characterized by skin abnormalities, such as café-au-lait macules and skinfold freckling, as well as peripheral nerve sheath tumors such as neurofibromas, schwannomas, and various other tumors. A 28-year-old man with a history of NF-1 presented to our facility with rectal bleeding. A rectal mass was subsequently discovered on colonoscopy and subsequent imaging. This mass was biopsied with histopathology consistent with a low-grade schwannoma. Schwannomas, while less common in NF-1 than NF-2, do sometimes occur in NF-1 patients, most commonly along the cranial, spinal, or peripheral nerves. These tumors also rarely occur in the gastrointestinal tract and even more rarely within the rectum specifically. Schwannoma must be considered in the differential for any rectal mass discovered in a patient with NF-1, so that the patient can be appropriately managed and treated.