Carcinoid syndrome caused by a serotonin-secreting pituitary tumour

Abstract

Neuroendocrine tumours are most frequently located in the gastrointestinal organ system or in the lungs, but they may occasionally be found in other organs. We describe a 56-year-old woman suffering from a carcinoid syndrome caused by a large serotonin-secreting pituitary tumour. She had suffered for years from episodes of palpitations, dyspnoea and flushing. Cardiac disease had been suspected, which delayed the diagnosis, until blood tests revealed elevated serotonin and chromogranin A in plasma. The somatostatin receptor (SSR) scintigraphy showed a single-positive focus in the region of the pituitary gland and MRI showed a corresponding intra- and suprasellar heterogeneous mass. After pre-treatment with octreotide leading to symptomatic improvement, the patient underwent trans-cranial surgery with removal of the tumour. This led to a clinical improvement and to a normalisation of SSR scintigraphy, as well as serotonin and chromogranin A levels. To our knowledge, this is the first reported case of a serotonin-secreting tumour with a primary location in the pituitary.