Pheochromocytoma is a rare neuroendocrine tumor which derives from chromaffin cells of the adrenal gland or relevant to sympathetic nerves and ganglia. The clinical features of pheochromocytoma are various. Paroxysmal episodes of serious hypertension, headache, palpitation, and diaphoresis are the typical manifestations (Bravo, 2004). Hypotension shock, pulmonary edema, and acute coronary syndrome induced by pheochromocytoma are uncommon (Malindretos et al., 2008;Batisse-Lignier et al., 2015). In this study, we present a rare case of cystic pheochromocytoma causing recurrent hypotension shock, non-cardiogenic pulmonary edema, and acute coronary syndrome, and the possible mechanisms are discussed.A 54-year-old woman presented to the emergency department with recurrent chest pain and dyspnea for 2 years, which have been aggravated for 4 h. She had no complaints of headache, cough, or palpitation. She had a history of pollen allergy but no other disease. On physical examination, the patient was afebrile. Her heart rate was 95 beats/min, blood pressure was 105/78 mmHg, respiratory rate was 21 breaths per minute, and oxygen saturation was 93% in ambient air. Much moist rale was audible, and examination of heart and abdomen had no abnormal findings. Emergency troponin I increased (2.34 µg/L; normal range 0-0.04 µg/L). An initial electrocardiogram (ECG) showed V4-V6 ST depression. Coronary angiography and computed tomography (CT) pulmonary angiogram were normal. Contrast-enhanced CT of the chest showed diffuse lesions in the lungs, large numbers of alveoli with inflammatory exudation (Fig. S1). IgE was positive, and influenza A and B virus antigens were negative. Brain natriuretic peptide was normal (62.7 pg/ml; normal range 0-100 pg/ml). The transthoracic echocardiogram was normal and left ventricular ejection fraction was 71.7%. She developed shock with hypotension (68/34 mmHg), and was stabilized with dopamine and norepinephrine for about 30 h. The initial diagnosis was hypersensitivity pneumonitis. After treatment with methylprednisolone and antibiotics, the patient got well and was discharged. One week later, serious chest pain and dyspnea attacked again, and abdomen B ultrasound showed weak echo mass (about 4 cm×3.5 cm×3.5 cm) in the retroperitoneum. Contrast-enhanced magnetic resonance imaging showed a cystic lesion of the left adrenal gland, which was considered as pheochromocytoma (Fig. 1). The patient recovered after surgery, and histological analysis (Fig. 2) confirmed the diagnosis of pheochromocytoma. At 1 year of follow-up, there was no recurrence of chest pain.Pheochromocytoma has an estimated incidence of 0.005%-0.100% in the worldwide population and 0.1%-0.6% in the hypertension population (Omura et al.,