Use of 2-tracer PET to diagnose gastrointestinal stromal tumour and pheochromocytoma in patients with Carney triad and neurofibromatosis type 1.

There is rapid evolution in the functional imaging of tumours. In two patients with concomitant pheochromocytoma and gastrointestinal stromal tumour (GIST), previously unrecognized tumours were visualized by combined 2-tracer positron emission tomography (PET), which also provided precise information about tumour type. PET imaging led to radical resection and the diagnoses were histopathologically confirmed. GISTs from the Carney patient and the patient with neurofibromatosis type 1 (NF1) both lacked KIT mutations.