ANSWER 43
The symptoms she describes raise the possibility of a 5-hydroxytryptamine (5-HT)-secreting
carcinoid tumour. The typical clinical features of the carcinoid syndrome are facial flush-
ing, abdominal cramps and diarrhoea. Sometimes there is asthma and right-sided heart
valve problems. The symptoms are characteristically intermittent and may come at times of
increased release on activity. Skin changes may be persistent.
The CT scan of the liver shows a space-occupying lesion in the liver likely to represent a
metastasis to the liver. Fluid-containing cystic lesions are of lower density. Other second-
ary tumours would give a similar appearance. Carcinoids do not generally produce their
symptoms until they have metastasized to the liver from their original site, which is usu-
ally in the small bowel. In the small bowel the tumours may produce local symptoms of
obstruction or bleeding.
The symptoms of carcinoid tumours are related to the secretion of 5-HT by the tumour.
The diagnosis depends on finding a high level of the metabolite 5-hydroxyindole acetic
acid (5-HIAA) in a 24-h collection of urine. Histology can be obtained from a liver biopsy
guided to the correct area by ultrasound or CT.
The symptoms can be controlled by antagonists of 5-HT such as cyproheptadine or by
inhibitors of its synthesis p-chlorophenylalanine, or release, octreotide. The tumour can be
reduced in size with consequent lessening of symptoms by embolization of its arterial supply
using interventional radiology techniques.
When odd symptoms such as those described here occur, the diagnosis of carcinoid tumour
should always be remembered and investigated. In real life, most of the investigations for
suspected carcinoid turn out to be negative.
Carcinoid tumours can occur in the lung when they act as slowly growing malignant
tumours. From the lung they can eventually be associated with left heart-valve problems.
The other typical carcinoid features occur only after metastasis to the liver.
- Intermittent skin flushing, diarrhoea, wheezing and abdominal cramps are symptoms of
the carcinoid syndrome. - All these symptoms have much commoner causes.
- Metastasis to the liver is present before the symptoms of carcinoid syndrome occur.