A 36-year-old male patient initially presented with hypertension, tinnitus, bilateral carotid masses, a right jugular foramen, and a periaortic arch mass with an elevated plasma dopamine level but an otherwise normal biochemical profile. On surveillance MRI 4 years after initial presentation, he was found to have a 2.2-cm T2 hyperintense lesion with arterial enhancement adjacent to the gallbladder, which demonstrated avidity on ⁶⁸Ga-DOTATATE PET/CTand retrospectively on ¹⁸F-FDOPA PET/CT but was nonavid on ¹⁸F-FDG PET/CT. Biochemical work-up including plasma catecholamines, metanephrines, and chromogranin A levels were found to be within normal limits. This lesion was surgically resected and was confirmed to be a paraganglioma (PGL) originating from the gallbladder wall on histopathology. Pheochromocytoma (PHEO) and PGL are rare tumors of the autonomic nervous system. Succinate dehydrogenase subunit D (SDHD) pathogenic variants of the succinate dehydrogenase complex are usually involved in parasympathetic, extra-adrenal, multifocal head, and neck PGLs. We report an unusual location of PGL in the gallbladder associated with SDHD mutation which could present as a potential pitfall on ¹⁸F-FDOPA PET/CT as its normal excretion occurs through biliary system and gallbladder. This case highlights the superiority of ⁶⁸Ga-DOTATATE in comparison to ¹⁸F-FDOPA and ¹⁸F-FDG in the detection of SDHD-related parasympathetic PGL.ClinicalTrials.gov Identifier: NCT00004847.
Adult ; Autonomic Nervous System ; Biliary Tract ; Catecholamines ; Chromogranin A ; Dopamine ; Gallbladder ; Head ; Humans ; Hypertension ; Magnetic Resonance Imaging ; Male ; Neck ; Paraganglioma ; Pheochromocytoma ; Plasma ; Positron-Emission Tomography and Computed Tomography ; Retrospective Studies ; Succinate Dehydrogenase ; Tinnitus

A 36-year-old male patient initially presented with hypertension, tinnitus, bilateral carotid masses, a right jugular foramen, and a periaortic arch mass with an elevated plasma dopamine level but an otherwise normal biochemical profile. On surveillance MRI 4 years after initial presentation, he was found to have a 2.2-cm T2 hyperintense lesion with arterial enhancement adjacent to the gallbladder, which demonstrated avidity on ⁶⁸Ga-DOTATATE PET/CTand retrospectively on ¹⁸F-FDOPA PET/CT but was nonavid on ¹⁸F-FDG PET/CT. Biochemical work-up including plasma catecholamines, metanephrines, and chromogranin A levels were found to be within normal limits. This lesion was surgically resected and was confirmed to be a paraganglioma (PGL) originating from the gallbladder wall on histopathology. Pheochromocytoma (PHEO) and PGL are rare tumors of the autonomic nervous system. Succinate dehydrogenase subunit D (SDHD) pathogenic variants of the succinate dehydrogenase complex are usually involved in parasympathetic, extra-adrenal, multifocal head, and neck PGLs. We report an unusual location of PGL in the gallbladder associated with SDHD mutation which could present as a potential pitfall on ¹⁸F-FDOPA PET/CT as its normal excretion occurs through biliary system and gallbladder. This case highlights the superiority of ⁶⁸Ga-DOTATATE in comparison to ¹⁸F-FDOPA and ¹⁸F-FDG in the detection of SDHD-related parasympathetic PGL.ClinicalTrials.gov Identifier: NCT00004847.