Endocrine Abstracts

Case history: A 69-year-old Caucasian male presented with persistent abdominal pain and was found to have a large right adrenal mass on CT. Interestingly his family history revealed that his daughter had been treated for Cushing’s disease. He was normotensive and denied classical symptoms of catecholamine excess. He had exertional dyspnoea in keeping with COPD. Subsequent tests were consistent with a secretory phaeochromocytoma and urine normetadrenaline 85,671 nmol/day (<4,400 nmol/day), metadrenaline 39,110 nmol/day (<2,00 nmol/day) and 3-methoxytyramine 3,154 nmol/day (<2,500 nmol/day). He was commenced on alpha- and beta-blockade. Whilst on holiday, prior to surgery, he collapsed with abdominal pain and developed severe watery diarrhoea.

Investigations: Blood tests on admission to A/E revealed acute renal failure with profound hypokalaemia. Stool samples tested negative for bacterial and parasitic infections but the life-threatening high volume diarrhoea continued, requiring large volumes of fluid resuscitation. A repeat CT abdomen was in keeping with new central necrosis.

Results and treatment: The patient was transferred, due to the difficult to manage severe diarrhoea and for consideration of an octreotide infusion. After 10 days and significant weight loss, the diarrhoea started to abate and five weeks later he underwent an open right adrenalectomy with an uneventful recovery period. Results received post-operatively revealed that his fasting gut peptides on transfer showed vasoactive intestinal peptide (VIP) levels of 300 pmol/l (<30). Subsequent post-operative fasting VIP levels were undetectable. Histology confirmed a phaeochromocytoma with a Ki-67 of up to 20% and SDHB immunohistochemistry was normally expressed.

Points for discussion: We present a rare complication, which we attribute to the partial infarction of a large secretory phaeochromocytoma. We will discuss the propensity of large phaeochromocytomas to undergo infarction or bleeding, which in turn can lead to a crisis. In this case the alpha and beta- blockade partially protected the patient from the catecholamine surge but the unexpected release of VIP was life threatening in itself. The timing of surgery for phaeochromocytomas remains a difficult clinical balance weighing up the benefits of a period of blockade versus the potential risks of having a ‘blocked’ phaeochromocytoma in situ. The fact that many phaeochromocytomas make other peptides adds to the uncertainty and we will discuss the peptides that can contribute to these management difficulties.