Endocrine Abstracts

Introduction: Pheochromocytomas are rare catecolamin-secreting neoplasms. The classic triad of symptoms in patients with a pheochromocytoma consists of episodic headache, sweating and tachycardia. Gastrointestinal spectrums have been reported such as chronic constipation, intestinal pseudo-obstruction or even intestinal perforation. We describe patient who presented with non-mechanical bowel obstruction and interestingly hydronephrosis and acute kidney injury as a consequence of an underlying, undiagnosed phaeochromocytoma.

Case report: A-58-year-old man was admitted to the emergency unit with complaints of generalized abdominal pain, constipation and vomiting. The patient had a medical history of hypertension. On initial examination, he had a blood pressure of 180/120 mmHg. He was clinically dehydrated. Abdominal examination confirmed a distended abdomen with reduced bowel sounds. The laboratory investigation results were as follows: creatinine 3.4 mg/dl (0.7–1.1), BUN 127 mg/dl (8.4–25.7). Abdominal radiography showed distended large bowel loops. A CT was arranged and this revealed a unilateral 5 cm right adrenal tumor with bilateral moderate hydroureteronephrosis but no structural cause for the bowel obstruction or hydronephrosis. He required haemodialysis several times because of severe uremia and progressive kidney disease. The patient’s serum and 24-hour urine catecholamine levels were high, confirming the diagnosis of phaeochromocytoma. Alpha blockade with doxazosin was administered to control his blood pressure and other symptoms. The hydronephrosis and intestinal pseudo obstruction findings were improved with adequate preoperative alpha blockade. He subsequently underwent uneventful surgical excision of the adrenal tumor. He remained well on follow-up after surgery and the antihypertensive drugs were stopped before discharge.

Discussion: Phaeochromocytoma may clinically manifest as a wide spectrum of gastrointestinal symptoms. The net effect of sympathetic over activity on the α and β-adrenergic receptors is a depressed peristaltic state and constriction of the sphincter, leading to ileus and constipation, as seen in this case. Another interesting feature observed in this patient was the presence of bilateral non-obstructive hydronephrosis. Because of the relaxation effect of the sympathetic system on the bladder and the construction of the internal uretral sphincher, excessive sympathetic stimulation can cause urinary retention and hydroureteronephrosis. This case report draws attention to the patients presenting with adrenal mass and unexplained ileus, constipation and non-obstructive hydroutereronephrosis the diagnosis of a pheochromocytoma should be considered. Our case demonstrates the successful outcome that can be achieved with appropriate medical and surgical intervention, as a delayed diagnosis can cause unfortunate consequences.