LAUSR

Rationale: Malignant pheochromocytoma is a rare disease and surgical resection is the only curative treatment. Patient concerns: An 81-year-old man of Chinese ethnicity was found to have a giant retroperitoneal tumor. Diagnoses: B-scan ultrasonography and CT scan presented a mass above the left kidney, measuring 13.5 × 10 .6 × 9.8 cm. Subsequent analysis of 24-h urinary catecholamines and vanillylmandelic acid, as well as of blood catecholamines and blood cortisol, showed no elevated levels. Interventions: The patient was treated with surgery. Outcomes: The result from immunohistochemical staining confirmed the presence of malignant pheochromocytoma. After three months follow-up, the blood pressure and serum potassium were all within normal limits, no post-operative complications, no tumor recurrence and metastasis were found. Lessons: This is the oldest patient known to have histologic documentation of this disease. Giant malignant pheochromocytomas are rare entities requiring clinical suspicion coupled with strategic diagnostic evaluation to confirm the diagnosis, personalized therapeutic treatment is required, particularly among elderly population.