A Rare Coexistence of Pheochromocytoma and Parkinson\u27s Disease With Diagnostic Challenges

We herein report a case of pheochromocytoma occurring in the course of Parkinson’s disease. The coexis-tence of these two disease is extremely rare, with only four cases hitherto reported across the public data-bases. It is also noteworthy that biochemical tests, which are critical for the diagnosis of pheochromocytoma, are severely confounded by dopaminergic medications fo r Parkinson’s disease, highlighting the importance of image-based modalities in this setting. We further attemp ted to gain insight into the potential molecular mechanisms, proposing that hypoxia-inducible factor signaling could make these two diseases mutually ex-clusive, while excessive reactive oxygen species could enable their coexistence