Pheochromocytomas are rare but clinically important chromaffin cell tumors that constitute a surgically correctable cause of chronic hypertension. The clinical features and consequences of pheochromocytoma result from release of catecholamines (e.g., norepinephrine and epinephrine) by the tumor. In our protocol studies we would like to find out whether the measurement of plasma metanephrines is the most sensitive biochemical test to diagnose the tumor and whether fluorodopamine positron emission tomography (PET) scanning will improve our ability to localize a pheochromocytoma. In addition, we wish to find out if there are any specific genetic or other markers to predict the course, malignant potential, and recurrence of pheochromocytoma. To date forty patients with known or clinically suspected pheochromocytoma underwent PET scanning after i.v. injection of 6-[18F]fluorodopamine. [18F]fluorodopamine localized the tumor in 28 patients. All patients with normal plasma levels of metanephrines had negative 6-[18F]fluorodopamine PET scans. This concludes that 6-[18F]Fluorodopamine PET scanning can detect and localize pheochromocytomas in patients known to harbor the tumor. Patients in whom the tumor is considered but excluded because of negative plasma metanephrine results have negative 6-[18F]fluorodopamine PET scans. These preliminary findings justify 6-[18F]fluorodopamine PET scanning as a diagnostic tool. In our studies of biochemical diagnosis to date, plasma metanephrines had a sensitivity of 99% and specificity of 90%. The new cloidine test coupled with the measurement of plasma metanephrines is the most promising test to rule out pheochromocytoma in patients presenting with symptoms that resemble the presence of the tumor. Inherited mutations of the RET protooncogene are tumorigenic in patients with multiple endocrine neoplasia type 2. However, it is not understood why only a few of the affected cells in the target organs develop into tumors. Genetic analysis of 9 pheochromocytomas from 5 unrelated patients with MEN 2 showed either duplication of the mutant RET allele in trisomy 10 or loss of the wild-type RET allele. Through either duplication of the mutant allele or loss of the wild-type allele, our results suggest a """"""""second hit"""""""" causing a dominant effect of the mutant RET allele as a possible mechanism for pheochromocytoma tumorigenesis in patients with MEN 2. Finally, our laboratory is currently attempting to establish pheochromocytoma cell cultures and used new techniques such as microarray analysis to trace back phenotypic differences in tumors to underlying differences in gene expression and ultimately to the basic somatic or germline mutations responsible for the tumor.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
U.S. National Inst/Child Hlth/Human Dev
United States
Zip Code
Taïeb, David; Jha, Abhishek; Guerin, Carole et al. (2018) 18F-FDOPA PET/CT Imaging of MAX-Related Pheochromocytoma. J Clin Endocrinol Metab 103:1574-1582
Fliedner, Stephanie M J; Lehnert, Hendrik; Pacak, Karel (2010) Metastatic paraganglioma. Semin Oncol 37:627-37
He, J; Makey, D; Fojo, T et al. (2009) Successful chemotherapy of hepatic metastases in a case of succinate dehydrogenase subunit B-related paraganglioma. Endocrine 36:189-93
Suh, Insoo; Shibru, Daniel; Eisenhofer, Graeme et al. (2009) Candidate Genes Associated With Malignant Pheochromocytomas by Genome-Wide Expression Profiling. Ann Surg :
Lai, Edwin W; Joshi, Bharat H; Martiniova, Lucia et al. (2009) Overexpression of interleukin-13 receptor-alpha2 in neuroendocrine malignant pheochromocytoma: a novel target for receptor directed anti-cancer therapy. J Clin Endocrinol Metab 94:2952-7
Martiniova, Lucia; Lai, Edwin W; Elkahloun, Abdel G et al. (2009) Characterization of an animal model of aggressive metastatic pheochromocytoma linked to a specific gene signature. Clin Exp Metastasis 26:239-50
Ilias, Ioannis; Pacak, Karel (2008) A clinical overview of pheochromocytomas/paragangliomas and carcinoid tumors. Nucl Med Biol 35 Suppl 1:S27-34
Ilias, Ioannis; Chen, Clara C; Carrasquillo, Jorge A et al. (2008) Comparison of 6-18F-fluorodopamine PET with 123I-metaiodobenzylguanidine and 111in-pentetreotide scintigraphy in localization of nonmetastatic and metastatic pheochromocytoma. J Nucl Med 49:1613-9
Pasini, Barbara; McWhinney, Sarah R; Bei, Thalia et al. (2008) Clinical and molecular genetics of patients with the Carney-Stratakis syndrome and germline mutations of the genes coding for the succinate dehydrogenase subunits SDHB, SDHC, and SDHD. Eur J Hum Genet 16:79-88
Scholz, Tim; Eisenhofer, Graeme; Pacak, Karel et al. (2007) Clinical review: Current treatment of malignant pheochromocytoma. J Clin Endocrinol Metab 92:1217-25

Showing the most recent 10 out of 64 publications