Carcinoid syndrome is a paraneoplastic complication of neuroendocrine tumours resulting from the release of hormones such as serotonin, and can result in significant morbidity. Somatostatin analogues are first-line treatment for symptom control. We report the case of severe carcinoid syndrome requiring high doses of octreotide and adjuvant therapies.
A 50-year-old subcontinental male presented with profuse diarrhoea and flushing. This occurred on a background of large cell neuroendocrine lung carcinoma which had been resected 8 years prior, including a second operation after involvement of the surgical margin. However, he had been lost to follow-up prior to administration of adjuvant therapy.
Investigations demonstrated elevated urinary 5-hydroxyindoleacetic acid 79umol/day (<30umol/day). Stool culture and PCR were normal. CT chest, abdomen and pelvis and 68Ga-DOTATATE PET/CT identified recurrence at the lobectomy site, as well as lesions in the pleura, trachea, vertebrae, and liver suggestive of metastases (liver SUVmax <17.9). Biopsy of the tracheal and liver lesions demonstrated well-differentiated neuroendocrine tumour.
Subcutaneous octreotide 50mcg BD was commenced with initial symptomatic response. However, diarrhoea worsened resulting in recurrent hypotensive episodes requiring ICU admission, vasopressor support, intravenous fluids and significant uptitration of intravenous octreotide to 120mcg/hour (total 2,880mcg/day) without acute complications. Telotristat, a tryptophan hydroxylase inhibitor and ondansetron, a serotonin receptor antagonist, were added for further symptomatic relief [1,2]. Once more clinically stable, angioembolisation of the liver lesion was performed, enabling his octreotide infusion to be weaned. He has subsequently transitioned to a lower dose subcutaneous octreotide alone without recurrence of diarrhoea or hypotension. Longer-term management of the underlying neuroendocrine tumour with peptide receptor radionuclide therapy with 177Lutetium or systemic therapies have yet to be finalised.
This case demonstrates the management of severe carcinoid syndrome, and the short-term ability to effectively and safely administer higher doses of intravenous octreotide than typically recommended.