Paraganglioma with acute hyperamylasaemia masquerading as acute pancreatitis

Ho ETL, Gardner DS
Correspondence: Dr Emily Ho, emily.ho@sgh.com.sg

ABSTRACT
Phaeochromocytomas are rare catecholamineproducing tumours. Although classically described to present with headache, diaphoresis and palpitations, they also present in unusual ways; hyperamylasaemia is one such rare presentation. We describe a man with an extra-adrenal phaeochromocytoma (paraganglioma) presenting with diaphoresis, abdominal pain and multi-organ failure. He had hyperamylasaemia of 1,087 (normal range [NR] 44–161) U/L, which mimicked acute severe pancreatitis. Serum lipase and radiographic imaging of the pancreas appeared normal, and the serial amylase levels normalised over six days upon stabilisation of his condition. 24-hour urinary metanephrines of 10,406 (NR 400–1,500) nmol/day suggested a catecholamine-secreting tumour, and metaiodobenzylguanine scintigraphy confirmed this. We postulate that amylase (of the salivary isotype) is released by hypoxic
tissues when high catecholamine levels cause vasoconstriction and that fluctuating hypotension decreases organ perfusion. This case highlights the need for awareness of rare presentations of phaeochromocytomas and encourages physicians to rethink the diagnosis
when investigations are inconsistent.

Keywords: hyperamylasaemia, pancreatitis, phaeochromocytoma
Singapore Med J 2011; 52(12): e251-e254