Endocrine Abstracts

Carcinoid tumours are neuroendocrine tumours characterised by production of serotonin (5-hydroxytriptamine, 5-HT) and tachykinins. Carcinoid syndrome occurs approximately in 10% of carcinoid tumours and symptoms arise when these vasoactive substances enter the systemic circulation escaping hepatic degradation. This normally occurs with metastasis to the liver or bronchus.

We present a case of a 66-year-old woman who presented with carcinoid syndrome in the absence of liver metastasis. She initially presented to neurology clinic with symptoms of ‘flashing lights’. She has a past medical history of hypertension, migraine, Graves’ disease and has been diagnosed with irritable bowel disease in 2002. On direct questioning, she also admitted to intermittent facial flushing with sweats, mild bronchospasm and an urticarial rash over her anterior thoracic wall.

She proceeded to have a 24-h collection for 5H1AA, which showed an elevated result of 326 μmol/24 h (normal range 0–42 μmol/24 h). This was repeated off interfering foodstuffs and was again elevated at 259 μmol/24 h. An octreotide scan confirmed a primary lesion in the small bowel. Plasma chomogranin A levels were raised at 315 pmol/l (normal range 0–60). A CT scan showed a significant mass of nodes at the root of mesentery with a small bowel primary but no hepatic lesions.

Her symptoms of carcinoid syndrome were due to direct drainage of serotonin and tachykinins via retroperitoneal shunts into the systemic circulation. An MIBG scan demonstrated areas of increased uptake involving left side of neck, mid abdomen and focal increase uptake involving the posterior mediastinum retrocrural region. She had no cardiac involvement. Treatment included trial of octreotide sub-cutanaeously initially then intramuscularly, which relieved her symptoms. It is likely the irritable bowel symptoms of diarrhoea from 7 years previously were related to the early stages of her carcinoid syndrome.