Cases of remission of psychosis following resection of pheochromocytoma or paraganglioma

The author previously proposed that schizophrenia has similar cytokine expression compared to melanoma, a neural crest cell tumor. One possible tumor model of schizophrenia includes anti-NMDA receptor encephalitis, a paraneoplastic syndrome. While examining the possible relationship of neural crest cell tumors to schizophrenia, the author found several case reports of psychosis resulting from pheochromocytomas and paragangliomas, types of neural crest cell tumors that secrete catecholamines. In most cases, surgical resection of the tumors resulted in remission of psychotic symptoms, and some remissions were associated with reduced levels of peripheral catecholamine levels. These reports suggest, first, that the differential diagnosis of psychosis with autonomic instability should include these tumors. Second, the cases raise a theoretical question as to how these tumors might cause psychosis. On one hand, the elevated peripheral catecholamines caused by these tumors generally agree with aspects of the dopamine hypothesis of schizophrenia although the mechanism of how peripheral dopamine would cause psychosis is unknown. On the other hand, these tumors could possibly secrete an unidentified antibody to a receptor similar to what is observed in anti-NMDA receptor encephalitis. (C) 2016 Elsevier B.V. All rights reserved.