A traumatic neuroma is a well-known complication after acute trauma to a peripheral nerve; the nerve tries to re-establish continuity by an orderly growth of axons from the peripheral to distal stump through the proliferation of Schwann cells. However, this process is not always perfect, and aberrant repair gives rise to a neuroma. We present a 50-year-old female who underwent an initial colonoscopy for change in bowel habits and was found to have a 7 mm submucosal lesion in the proximal rectum. Endoscopic ultrasound was done which showed a hypoechoic lesion in the submucosal plane without muscularis propria invasion. The patient underwent successful cap-assisted endoscopic mucosal resection of the lesion without complication. Pathology of the specimen revealed a traumatic rectal neuroma with immunostaining positive for S100. However, this patient did not have any known risk factors such as previous surgery including polypectomy or hemorrhoidectomy or any previous rectal manipulation. Interestingly, this is the second case of traumatic rectal neuroma reported in the English-language literature.
A traumatic neuroma develops from a non-neoplastic proliferation of the proximal end of a severed, partially transected, or injured nerve as a result of trauma or surgery. Most commonly, the lesion demonstrates pain whenever palpated or manipulated. The most common location for a traumatic neuroma is the lower extremity after an amputation, followed by the head and the neck area, especially the oral cavity after a tooth extraction [
A 50-year-old female with a past medical history of asthmatic bronchitis underwent an initial colonoscopy procedure after complaining of 3 weeks of loose nonbloody bowel movements. The patient denied any rectal pain or prior rectal manipulation. On colonoscopy, an incidental 7 mm submucosal nodule was seen in the proximal rectum at 12 cm from the anal verge (Figure
Endoscopic image showing a submucosal nodule in the rectum at the 3 o’clock position located 12 cm from the anal verge.
Rectal endoscopic ultrasound (EUS) showing a localized hypoechoic submucosal lesion with tiny hyperechoic bands without muscularis propria invasion. Muscularis mucosae (yellow arrow), submucosa (blue arrow), and muscularis propria (red arrow).
Endoscopic image showing
Endoscopic image showing successful closure of the rectal mucosal resection with two hemostatic clips.
Pathology images of the traumatic rectal neuroma. (a) Low-power view. Note the mucosa on the top (M), the muscularis mucosae (MM), and the submucosa (SM). The lesion contained in the submucosal (arrow). (b) High-power view of the neural cells in the submucosa comprised of haphazardly proliferating spindle cells.
Pathology images of Immunostaining for S100, which including spindle and epithelioid neuro cells.
Neuromas are benign neural proliferations that occur after nerve injury. A neuroma can occur after a laceration which results in micro-trauma of peripheral nerves from stretching or compression of local tissues and can arise 1–12 months after transection or injury [
Traumatic neuromas are divided into spindle neuroma and terminal neuroma. A spindle neuroma is characterized by an internal, focal, fusiform swelling secondary to constant friction or irritation due to a nondisrupted, injured, but intact nerve trunk [
In rat models, it has been demonstrated that inhibiting nerve growth factor (NGF) following nerve injury could reduce neuroma formation and neuropathic pain without damaging the cell bodies [
The usual presentation of a traumatic neuroma is of pain; however, our patient presented asymptomatically. This can possibly be attributed to the lack of somatic innervation within the rectal submucosa as opposed to neuromas located in an extremity. In the only other case report of a traumatic rectal neuroma, the authors hypothesized the lesion likely arose as a result of trauma to the submucosal Meissner’s plexus fibers or Auerbach’s plexus fibers after a previous polypectomy [
Informed written consent was obtained from the patient for publication of this report.
The authors declare that they have no conflicts of interest.