Case of the Month

CLINICAL

47 year old male with a one year history of intermittent severe abdominal pain

FINDINGS

Three images from a contrast-enhanced CT scan, optimised for small bowel visualisation.
Left Image: Coronal section. Primary ileal carcinoid and adjacent mesenteric lymph node mass (arrow)

Middle Image: Axial Section. The primary carcinoid tumour of the distal ileum can be clearly seen (arrow)

Right Image: Coronal Section, further posteriorly. The cicatrising nature of the mesentric mass can be appreciated with strands extending into the adjacent mesenteric fat.

DISCUSSION

Carcinoid tumours most commonly arise in the distal small bowel, but can be seen anywhere in the gastrointestinal tract, including the appendix, colon and stomach. They occur in the tracheobronchial tree.
They are rare in young people and have a peak incidence in the 7th decade.

Symptoms depend on site. Small bowel carcinoid tumours usually present with pain, abdominal mass or bowel obstruction. In the lungs, they usually present with cough, dyspnoea and haemoptysis.

A minority of patients with these tumours develop carcinoid syndrome, which is due to the secretion of 5HT and serotonin. These patients usually have hepatic metastases. The clinical manifestations of carcinoid syndrome include flushing, diarrhoea, bronchoconstriction and the development of cardiac valve disease.

The typical radiological signs of abdominal carcinoid are the presence of an abnormal mesenteric mass which has a cicatrising (scarring) appearance. This may be associated with kinking and obstruction of the bowel itself. This mass represents mesenteric lymph node metastases. The primary bowel lesion is often small and difficult to visualise.