Re: Metastatic pheochromocytoma to the pancreas diagnosed by endoscopic ultrasound‐guided fine needle aspiration: A case report and review of literature

Abstract

To the editor, We read the publication “Metastatic pheochromocytoma to the pancreas diagnosed by endoscopic ultrasound-guided fine needle aspiration: A case report and review of literature” by Shanna X. Yang et al with great interest. This brief report is about a “pancreatic metastatic pheochromocytoma.” Cytological features and immunohistochemical stains indicate that the tumor in the pancreas was a neuroendocrine tumor, combined with the left adrenal pheochromocytoma diagnosed by CT image, biochemical indicator, and iodine123-metaiodobenzylguanidine (MIBG) scan. A lesion in the pancreas was diagnosed with metastatic pheochromocytoma even though there was a lack of significant MIBG uptake in the pancreatic metastatic mass. However, according to the third edition of the WHO classification in 2004, metastatic pheochromocytoma could only be diagnosed when metastatic tumor occurs in a site that does not normally have a chromaffin cell population. However, there is chromaffin cell in the pancreas. So, in this study, a tumor in the pancreas should not be diagnosed with metastatic pheochromocytoma, but a pancreatic neuroendocrine tumor can, which explained the lack of significant MIBG uptake in the pancreatic lesion. Actually, the morbidity of adrenal pheochromocytoma and pancreatic neuroendocrine tumors at the same time could be caused by germline VHL mutation. VHL mutation is the pathogenesis of Von Hippel-Lindau (VHL) syndrome, which is a multisystemic tumor predisposition syndrome characterized by central nervous system and retinal hemangioblastomas, clearcell renal cell carcinoma, pheochromocytoma, pancreatic neuroendocrine tumors, and visceral cysts. In clinical practice, patients with adrenal pheochromocytoma and pancreatic neuroendocrine tumor would be suspected as having VHL syndrome and would be referred for a genetic test. Therefore, this patient should be genetically tested to ensure there is germline VHL mutation so that examinations be performed to check if there is other VHL syndrome-related disease and genetic consulting be carried out among the families if VHL syndrome is diagnosed.