Abstract
Giant pheochromocytomas are rare tumors, with the majority being clinically silent. Clinically manifesting pheochromocytoma can present with symptoms of catecholamine excess, but nonspecific symptoms and variable clinical patterns of hypertension make it difficult to diagnose. Missing the diagnosis can lead to cardiovascular catastrophes like a pheochromocytoma crisis and even death. We report a 45-year-old woman on antihypertensives, repeatedly visiting a hospital for recurrent headaches finally presented in a hypertensive crisis at an emergency department. Management was started along with an injection of labetalol, which led to an unpredicted abrupt blood pressure fall, and was successfully resuscitated. Imaging and plasma metanephrine studies revealed an underlying giant pheochromocytoma, which was cured after successful surgical resection. A high degree of clinical suspicion, elaborate and focused history-taking, and initial ultrasound imaging can guide us toward the early diagnosis of pheochromocytoma. Before the alpha blockade, beta-blockers should not be used in any cases of pheochromocytoma. KEYWORDS: case reports; headache; hypertension; pheochromocytoma.