Megarectum

Case contributed by Ian Bickle
Diagnosis almost certain

Presentation

Patient under general anesthesia performed for mandibular resection. Noted to have a pelvic mass.

Patient Data

Age: 14 years
Gender: Female
ct

The rectum to the rectosigmoid junction is massively distended measuring 11cm in axial diameter and is occupied by a large volume of impacted feces.

The bladder and uterus are displaced by the feculent filled rectum.

No proximal bowel obstruction.

Her original problem - a mandibular ameloblastoma is illustrated.

ct

Expansile lesion with cortical destruction in the body of the left mandible with an associated unerupted tooth.

Biopsy proven ameloblastoma.

Photo

Site of mandibular ameloblastoma

Case Discussion

Hirschsprung disease is the most common cause of neonatal colonic obstruction. It accounts for ~15-20% of all intestinal obstructions in the neonate.  It can present later in life, as in this perceived case.

The main differential is a functional megarectum.

In this case, it only came to light due to the dutiful examination of a maxillofacial surgeon, just prior to performing a mandibular resection for ameloblastoma.

Retrospective questioning indicated the patient has not emptied her bowel for 3 months!

The patient/patient guardian declined rectal biopsy to confirm the strong suspicion of late presentation of Hirschsprung's disease.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.