Pheochromocytoma Presenting with Acute Abdomen.

Pheochromocytoma, a neuroendocrine tumor of the adrenal medulla, arising from chromaffin cells, usually presents with the clinical triad of paroxysmal headache, profuse sweating and palpitations, associated with labile hypertension. Here, we present the case of an adult male with an unusual manifestation of pheochromocytoma in the form of acute pain abdomen with nausea and abdominal guarding, mimicking acute peritonitis. He had fluctuating blood pressure recordings. On subsequent investigation, a mass lesion in the left suprarenal area on an abdominal CT scan and a 24-hour urinary metanephrine assay confirmed the diagnosis of pheochromocytoma.