A patient with a large recurrent pheochromocytoma demonstrating the pitfalls of diagnosis.

Background: A 59-year-old man presented for a follow-up, 6 years after surgery for a large pheochromocytoma. He had suffered from diabetes mellitus, hypertension and abdominal pain in the right flank region. Previous postoperative follow-up did not reveal tumor recurrence.
Investigation: Measurement of plasma free metanephrine and normetanephrine by high-performance liquid chromatography and radioimmunoassay; 123I-metaiodobenzylguanidine (MIBG) scintigraphy; hybrid 123I-MIBG single-photon emission CT (SPECT)-CT; MRI; testing for plasma norepinephrine and epinephrine; intraoperative ultrasonography; histological staining for chromogranin A and synaptophysin; and postoperative 18F-dihydroxyphenylalanine (DOPA) PET scan.
Diagnosis: Recurrent pheochromocytoma.
Management: Laparotomy with tumor resection. Reduction of antihypertensive medications. Further follow-up by MRI, hybrid 123I-MIBG SPECT-CT and testing for plasma catecholamines and free metanephrines.