Pitfalls in the diagnosis of phaeochromocytoma
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《英国医生杂志》
1 Department of Internal Medicine, Kantonsspital Münsterlingen, CH-8596 Münsterlingen, Switzerland, 2 Division of Oncology, Department of Internal Medicine, University Hospital, Rümistrasse 100, CH-8091 Zürich, Switzerland
Correspondence to: M Krause martin.krause@stgag.ch
Introduction
This patient presented with poorly controlled blood pressure, which prompted the clinicians to search for secondary hypertension. Three classic pitfalls, however, led to the misdiagnosis of phaeochromocytoma. The first pitfall was that the finding of an adrenal tumour was related to hypertension. Adrenal tumours are incidentally found in 1.5% of computed tomograms; in a large survey, only 4.2% were found to be phaeochromocytomas. Thus the presence of an adrenal tumour together with hypertension is a coincidence in most of the cases.2 The second pitfall was the assumption that the high urinary dopamine levels were related to the tumour, and other causes for false positive catecholamine concentrations were not considered.3 4 Our patient was taking a moderate dose of levodopa with carbidopa. After the drug was stopped, dopamine levels returned to normal over a period of several weeks, indicating that this drug was responsible for the increased levels. The specificity of urinary catecholamines in sporadic cases of phaeochromocytoma is only 75%. Recently, the determination of levels of plasma free metanephrines has been recommended, which have a higher specificity and sensitivity for detection of phaeochromocytoma.5 The third pitfall was that a positive 123I-metaiodobenzylguanidine scan was thought to confirm the diagnosis of right sided phaeochromocytoma. The specificity of this scan is more than 95%, although accumulation of radionuclide in a dilated renal pelvis may give a false positive result.6 7
In this case, the sequence of positive tests misled the clinicians into suspecting a phaeochromocytoma. In a population of patients with therapy resistant hypertension and an adrenal mass, the prevalence of phaeochromocytoma is around 30%.5 The finding of increased levels of urinary catecholamines (sensitivity 91%, specificity 75%) double this probability.5 If 60% are taken as a pretest probability for next test, a positive 123I-metaiodobenzylguanidine scan (sensitivity 100%, specificity of 95%) increases the probability to 97%.8 A correct diagnosis of phaeochromocytoma depends on a critical interpretation of each diagnostic test, a thorough review of anatomical and functional examinations, and careful history taking, including drugs.
Careful drug history and critical review of all tests are essential to diagnose phaeochromocytoma
Contributors: LZ wrote the first draft of the paper; CT, JF, and MK contributed to revisions. LZ, JF, and MK cared for the patient while in hospital. LZ will act as guarantor for the paper.
Funding: None.
Competing interests: None declared.
References
Williams GH. Hypertensive vascular disease. In: Braunwald E, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL, eds. Harrison's principles of internal medicine, 15th ed. New York: McGraw-Hill. 2001: 1414-30.
Mantero F, Terzolo M., Arnaldi G, Osella G, Masini AM, Ali A, et al. A survey on adrenal incidentaloma in Italy. J Clin Endocrinol Metab 2000;85: 637-44.
Montastruc JL, Chamontin B, Senard JM, Tran MA, Rascol O, Llau ME, et al. Pseudophaeochromocytoma in parkinsonian patient treated with fluoxetine plus selegiline. Lancet 1993;1: 555.
Krentz AJ, Mikhail S, Cantrell P, Gavin MH. Pseudophaeochromocytoma syndrome associated with clozapine. BMJ 2001;322: 1213.
Lenders WM, Pacak K, Walther MM, Linehan WM, Mannelli M, Friberg P, et al. Biochemical diagnosis of pheochromocytoma. JAMA 2002;287: 1427-34.
Pacak K, Linehan WM, Eisenhofer G, Walther MM, Goldstein DS. Recent advances in genetics, diagnosis, localization, and treatment of pheochromocytoma. Ann Intern Med 2001;134: 315-29.
Mochizuki T, Murase K, Tauxe WN, Tanada S, Hamamoto K. A pseudopheochromocytoma? Accumulation of I-123 MIBG in the renal pelvis. Clin Nucl Med 1994;19: 1030-1.
Maurea S, Klain M, Caraco C, Ziviello M, Salvatore M. Diagnostic accuracy of radionuclide imaging using 131I nor-cholesterol or meta-iodobenzylguanidine in patients with hypersecreting or non-secreting adrenal tumours. Nucl Med Commun 2002;23: 951-60.(L Zendron, fellow1, J Feh)
Correspondence to: M Krause martin.krause@stgag.ch
Introduction
This patient presented with poorly controlled blood pressure, which prompted the clinicians to search for secondary hypertension. Three classic pitfalls, however, led to the misdiagnosis of phaeochromocytoma. The first pitfall was that the finding of an adrenal tumour was related to hypertension. Adrenal tumours are incidentally found in 1.5% of computed tomograms; in a large survey, only 4.2% were found to be phaeochromocytomas. Thus the presence of an adrenal tumour together with hypertension is a coincidence in most of the cases.2 The second pitfall was the assumption that the high urinary dopamine levels were related to the tumour, and other causes for false positive catecholamine concentrations were not considered.3 4 Our patient was taking a moderate dose of levodopa with carbidopa. After the drug was stopped, dopamine levels returned to normal over a period of several weeks, indicating that this drug was responsible for the increased levels. The specificity of urinary catecholamines in sporadic cases of phaeochromocytoma is only 75%. Recently, the determination of levels of plasma free metanephrines has been recommended, which have a higher specificity and sensitivity for detection of phaeochromocytoma.5 The third pitfall was that a positive 123I-metaiodobenzylguanidine scan was thought to confirm the diagnosis of right sided phaeochromocytoma. The specificity of this scan is more than 95%, although accumulation of radionuclide in a dilated renal pelvis may give a false positive result.6 7
In this case, the sequence of positive tests misled the clinicians into suspecting a phaeochromocytoma. In a population of patients with therapy resistant hypertension and an adrenal mass, the prevalence of phaeochromocytoma is around 30%.5 The finding of increased levels of urinary catecholamines (sensitivity 91%, specificity 75%) double this probability.5 If 60% are taken as a pretest probability for next test, a positive 123I-metaiodobenzylguanidine scan (sensitivity 100%, specificity of 95%) increases the probability to 97%.8 A correct diagnosis of phaeochromocytoma depends on a critical interpretation of each diagnostic test, a thorough review of anatomical and functional examinations, and careful history taking, including drugs.
Careful drug history and critical review of all tests are essential to diagnose phaeochromocytoma
Contributors: LZ wrote the first draft of the paper; CT, JF, and MK contributed to revisions. LZ, JF, and MK cared for the patient while in hospital. LZ will act as guarantor for the paper.
Funding: None.
Competing interests: None declared.
References
Williams GH. Hypertensive vascular disease. In: Braunwald E, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL, eds. Harrison's principles of internal medicine, 15th ed. New York: McGraw-Hill. 2001: 1414-30.
Mantero F, Terzolo M., Arnaldi G, Osella G, Masini AM, Ali A, et al. A survey on adrenal incidentaloma in Italy. J Clin Endocrinol Metab 2000;85: 637-44.
Montastruc JL, Chamontin B, Senard JM, Tran MA, Rascol O, Llau ME, et al. Pseudophaeochromocytoma in parkinsonian patient treated with fluoxetine plus selegiline. Lancet 1993;1: 555.
Krentz AJ, Mikhail S, Cantrell P, Gavin MH. Pseudophaeochromocytoma syndrome associated with clozapine. BMJ 2001;322: 1213.
Lenders WM, Pacak K, Walther MM, Linehan WM, Mannelli M, Friberg P, et al. Biochemical diagnosis of pheochromocytoma. JAMA 2002;287: 1427-34.
Pacak K, Linehan WM, Eisenhofer G, Walther MM, Goldstein DS. Recent advances in genetics, diagnosis, localization, and treatment of pheochromocytoma. Ann Intern Med 2001;134: 315-29.
Mochizuki T, Murase K, Tauxe WN, Tanada S, Hamamoto K. A pseudopheochromocytoma? Accumulation of I-123 MIBG in the renal pelvis. Clin Nucl Med 1994;19: 1030-1.
Maurea S, Klain M, Caraco C, Ziviello M, Salvatore M. Diagnostic accuracy of radionuclide imaging using 131I nor-cholesterol or meta-iodobenzylguanidine in patients with hypersecreting or non-secreting adrenal tumours. Nucl Med Commun 2002;23: 951-60.(L Zendron, fellow1, J Feh)