Rare Presentation of a Metastatic Pancreatic Neuroendocrine Neoplasm Presenting with Atrial Flutter.

Pancreatic neuroendocrine neoplasms (PanNENs) rarely secrete serotonin, which is the main cause of carcinoid syndrome. One of its unusual manifestations is carcinoid heart disease or Hedinger's syndrome which is seldom accompanied by cardiac arrhythmias. We report the case of an 88-year-old woman who presented with recently experienced episodes of palpitations and a newly developed atrial flutter with a ventricular rate of 130 beats per minute. Echocardiography revealed thickened and tethered tricuspid and pulmonary valve leaflets causing severe valvular regurgitation and right ventricular dilatation. Episodes of intermittent diarrhoea over the previous 2 years were mentioned, making carcinoid syndrome our working diagnosis. The 5-hydroxyindoleacetic acid (5-HIAA) levels in a 24-hour urine collection specimen were elevated. Conventional imaging studies and a Ga-68 dodecane tetraacetic acid tyrosine-3-octreotate (DOTATATE) positron emission tomography/computer tomography (PET/CT) scan revealed the presence of a metastatic PanNEN arising from the pancreatic tail. The patient was managed with lanreotide and telotristat with remarkable improvement of her symptoms. To our knowledge, this is the first reported case of carcinoid syndrome presenting with atrial flutter as the initial symptom. LEARNING POINTS: Ultrasonography findings can indicate or lead to the diagnosis of carcinoid heart disease or Hedinger's syndrome.Clinicians should investigate rarer causes of atrial flutter when common ones are excluded.Even in advanced metastatic disease, complete remission of symptoms may be achieved with somatostatin analogues along with telotristat ethyl. © EFIM 2021.