A case of pheochromocytoma with severe paralytic ileus

A rare and life-threatening cause of pseudo-obstruction in two surgical patients

We describe two patients who presented with non-mechanical bowel obstruction as a consequence of an underlying, undiagnosed phaeochromocytoma. The first patient was referred by his general practitioner with signs and symptoms of small bowel obstruction on a background of frequent constipation. An abdominal scan revealed an adrenal tumour (subsequently found to be a phaeochromocytoma) but no structural cause for obstruction. Treatment of the phaeochromocytoma was associated with prompt restoration of bowel function. The second patient was transferred to the intensive care unit on the 8th postoperative day following an elective hip joint replacement. Signs and symptoms of bowel obstruction together with labile blood pressure and progressive lactic acidosis prompted admission to the intensive treatment unit. An abdominal scan identified an infiltrative adrenal tumour but no mechanical cause for bowel obstruction. Histology confirmed a malignant phaeochromocytoma. Bowel obstruction as the presenting symptom of phaeochromocytoma is well described but rarely identified.

Emergencies caused by pheochromocytoma, neuroblastoma, or ganglioneuroma

Pheochromocytoma may lead to important emergency situations, ranging from cardiovascular emergencies to acute abdomen and multiorgan failure. It is vital to think about this disease in any emergency situation when conventional therapy fails to achieve control or symptoms occur that do not fit the initial diagnosis. The importance of keeping this diagnosis in minds is underscored by the fact that, in 50% of pheochromocytoma patients, the diagnosis is initially overlooked. Two other tumors of the sympathetic nervous system, neuroblastoma and ganglioneuroma, are less commonly associated with emergency conditions. If they occur, they are often linked to catecholamine excess, paraneoplastic phenomena, or local tumor mass effect.

Acute Intestinal Pseudo-obstruction

Acute pseudo-obstruction may manifest clinically in one of three forms--acute gastroparesis, ileus, and acute colonic pseudo-obstruction (Ogilvie's syndrome). Though formerly associated primarily with the postoperative state, these entities are increasingly recognized in association with a wide variety of major medical problems. There are few controlled studies to guide the clinician in the management of these disorders. Treatment remains largely empirical, and time-honored, based primarily on "bowel rest," nasogastric decompression, and supportive care. While a wide variety of pharmacologic approaches have been advocated, few have been subjected to, or survived, the rigors of a properly controlled trial. Neostigmine is a notable exception, and has been shown to be effective in Ogilvie's syndrome. Perforation is a significant threat in megacolon; colonoscopic, or surgical decompression may, therefore, be indicated. Both are associated with significant risks in this context, but may prevent progression to perforation with its attendant mortality. New approaches seek to exploit current concepts in the pathophysiology of ileus and megacolon but have not, as yet, achieved efficacy in human studies.

Pheochromocytoma and bowel ischemia

This case report presents a patient with an adrenal pheochromocytoma manifesting as intestinal ischemia. Emergency department and hospital courses are described. Complications of pheochromocytoma are briefly reviewed, with special reference to the gastrointestinal findings in this syndrome. The onset of gastrointestinal symptoms in patients with pheochromocytoma can be a herald of intestinal ischemia, necessitating prompt medical and surgical intervention.

Pheochromocytoma. Update on diagnosis, localization, and management

Pheochromocytoma, although rare, is associated with a high degree of morbidity and mortality if not recognized. A high degree of suspicion in patients with new-onset hypertension; hypertension with sudden worsening or development of diabetes mellitus; or a family history of MEN, neuroectodermal tumors, or simple pheochromocytoma should prompt biochemical confirmation with either 24-hour urine catecholamines (norepinephrine and epinephrine) or total MET (NMET plus MET). Following confirmation of the diagnosis, radiologic studies with CT and (if needed) MIBG are employed to localize the tumor. Surgical removal is the only definitive therapy. Medical management with alpha-blocking agents, to control symptoms and prevent a hypertensive crisis, is generally advocated for 2 weeks preoperatively and intraoperatively. Occasionally, beta-blockers, employed only after adequate alpha-blockade, are necessary to control tachycardia and tachyarrhythmias. High-dose MIBG and combination chemotherapy have been used adjunctively to treat malignant pheochromocytoma, although neither modality provides lasting satisfactory results. Normal urine assays performed 2 weeks postoperatively ensure the complete removal of all tumor. Additionally, lifelong follow-up (yearly initially) is necessary to detect any signs of benign recurrence or malignancy because these have been reported to occur as long as 41 years after the initial surgical resection. Biochemical evidence of excess catecholamine production usually precedes the clinical manifestations of catecholamine excess when these tumors recur.