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Adrenal: Pheochromocytoma Imaging Pearls - Learning Modules | CT Scanning | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ Adrenal ❯ Pheochromocytoma

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  • “Hereditary syndromes associated with pheochromocytomas and EAPs include multiple endocrine neoplasia (MEN) syndrome types 2A and 2B, neurofibromatosis type 1 (NF-1), von Hippel–Lindau disease (VHL), and familial paraganglioma syndrome (PGL), as outlined in the Table. These syndromes are associated with germline mutations that activate the RET gene (MEN), inactivate the NF-1gene (NF-1), inactivate the VHL gene (VHL), and inactivate the genes for succinate dehydrogenase (SDH) subunits B, C, or D (PGL). Problematically, the well-recognized syndromes associated with these mutations may be clinically silent. Thus, many neuroendocrine tumors previously thought to be sporadic (due to an absence of syndromic stigmata) harbor underlying mutations.”


    From the Radiologic Pathology Archives: Adrenal Tumors and Tumor-like Conditions in the Adult: Radiologic-Pathologic Correlation
Grant E. Lattin, Jr et al.
RadioGraphics 2014 34:3, 805-829 
  • “Pheochromocytomas tend to have different CT imaging features mimicking other tumors according to the size of the tumors. However, clinical features, CT imaging characteristics, and radioisotope activity are not different between small and large pheochromocytomas.”

    
Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas.
Kim DW et al.
Clin Imaging. 2017 May - Jun;43:153-157
  • “Pheochromocytomas are typically round or oval masses that range in size from 1 to 10 cm or more. CT imaging usually shows avid enhancement and washout. These tumors may be complicated by varying degrees of degeneration, hemorrhage, necrosis, fibrosis, or cystic changes. Their various imaging features have earned these tumors the nickname of an “imaging chameleon”.

    Pheochromocytomas may mimic adrenal adenoma, adrenal cortical carcinoma, or metastasis, and are not usually diagnosed by CT alone.”
Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas
Kim DW et al.
Clinical Imaging (in press)
  • “Reinig, et al. noted that smaller pheochromocytomas tend to be homogeneous, while larger masses tend to be heterogeneous due to hemorrhage and necrosis. However, differences in clinical features and other radiologic features between small and large pheochromocytomas have not been well studied.”


    Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas
Kim DW et al.
Clinical Imaging (in press)
  • “Approximately 5% of adrenal incidentalomas are pheochromocytomas. Although initial reports found that 11% of pheochromocytomas were found incidentally, due to the increased use of CT, more recent studies have reported an incidental adrenal pheochromocytomas rate of 44–58%. The incidental rate of discovery in those studies did not differ with the incidental rate of 58.9% (23 of 39 cases) in this study.”


    Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas
Kim DW et al.
Clinical Imaging (in press)
  • “There was a trend for smaller pheochromocytomas (6 of 10, 60%) to meet CT washout criteria for adenomas compared with larger pheochromocytomas (9 or 29, 31%), although this difference was not significant. Pheochromocytomas appearing as small and homogeneous adrenal masses with adenoma-like washout values by only adrenal protocol CT would be falsely diagnosed as adenoma and may be not be worked up further. In our study, five cases with small pheochromocystomas were falsely diagnosed as adenomas. However, these five cases had positive biochemical test results. Therefore, clinical features and biochemical tests should also be considered when diagnosing adrenal masses.”


    Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas
Kim DW et al.
Clinical Imaging (in press)
  • “In conclusion, clinical features, CT imaging characteristics, and radioisotope activity are not significantly different between large and small pheochromocytomas. However, smaller pheochromocytomas were more likely to meet CT washout criteria for adenomas compared with larger pheochromocytomas, although this difference was not statistically significant.”


    Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas
Kim DW et al.
Clinical Imaging (in press)
  • “In 40 (70.2%) of the 57 patients, an adrenal pheochromocytoma was detected in an imaging study performed without suspicion of an adrenal lesion. There were 13 chest computed tomography studies-8 to evaluate for possible pulmonary emboli. Other indications included abdominal pain or discomfort (n = 8), trauma (n = 3), abnormal liver function tests (n = 3), suspect renal artery stenosis (n = 3), hematuria (n = 2), colitis (n = 2), and 4 miscellaneous indications.”


    Serendipity in the diagnosis of pheochromocytoma.
Oshmyansky AR et al
J Comput Assist Tomogr. 2013 Sep-Oct;37(5):820-3
  • “In a 7-year period at a single institution, 40 patients, 70% of new cases of surgically proven pheochromocytoma, were initially detected by serendipity.”


    Serendipity in the diagnosis of pheochromocytoma.
Oshmyansky AR et al
J Comput Assist Tomogr. 2013 Sep-Oct;37(5):820-3
  • “The aim of the study was to evaluate the prevalence of pheochromocytoma (PHEO) in patients with neurofibromatosis type 1 (NF1), and to analyze the behavior of some anthropometric and cardiovascular parameters. In 48 consecutive NF1 patients, urinary metanephrines and vanillylmandelic acid excretion were assessed. The body mass index (BMI), waist circumference (WC), ambulatory blood pressure monitoring (ABPM), echocardiography and ultrasound carotid arterial wall evaluation were performed. In NF1 patients, 11 (29.3%) had arterial hypertension, 7 (14.6%) had a PHEO. Four (57%) NF1 patients with PHEO were symptomatic at the diagnosis. In PHEO-NF1 patients, we revealed a lower BMI and WC values with respect to NF1 patients without PHEO and normal subjects (NSs) (p < 0.05), respectively. The nocturnal non-dipping pattern at the ABPM was present in 40.4% of NF1 patients, and in particular this phenomenon was present in PHEO-NF1 patients (71.4%). Left ventricular mass index and intima media thickness were significantly higher in NF1 patients as compared to NS (p < 0.05), particularly in NF1-PHEO patients (p < 0.05). In conclusions, these findings revealed high prevalence of PHEO in NF1 patients and suggest that, in addition to blood pressure, humoral factors (increased sympathetic activity or neurofibromin), influence the pathogenesis of remodeling of cardiovascular system.”


    Neurofibromatosis type 1 (NF1) and pheochromocytoma: prevalence, clinical and cardiovascular aspects.
Zinnamosca L et al.
Arch Dermatol Res. 2011 Jul;303(5):317-25.
  • “The aim of the study was to evaluate the prevalence of pheochromocytoma (PHEO) in patients with neurofibromatosis type 1 (NF1), and to analyze the behavior of some anthropometric and cardiovascular parameters. In 48 consecutive NF1 patients, urinary metanephrines and vanillylmandelic acid excretion were assessed. The body mass index (BMI), waist circumference (WC), ambulatory blood pressure monitoring (ABPM), echocardiography and ultrasound carotid arterial wall evaluation were performed. In NF1 patients, 11 (29.3%) had arterial hypertension, 7 (14.6%) had a PHEO. Four (57%) NF1 patients with PHEO were symptomatic at the diagnosis. In PHEO-NF1 patients, we revealed a lower BMI and WC values with respect to NF1 patients without PHEO and normal subjects (NSs) (p < 0.05), respectively.”


    Neurofibromatosis type 1 (NF1) and pheochromocytoma: prevalence, clinical and cardiovascular aspects.
Zinnamosca L et al.
Arch Dermatol Res. 2011 Jul;303(5):317-25.
  • “The aim of the study was to evaluate the prevalence of pheochromocytoma (PHEO) in patients with neurofibromatosis type 1 (NF1), and to analyze the behavior of some anthropometric and cardiovascular parameters. In 48 consecutive NF1 patients, urinary metanephrines and vanillylmandelic acid excretion were assessed. The body mass index (BMI), waist circumference (WC), ambulatory blood pressure monitoring (ABPM), echocardiography and ultrasound carotid arterial wall evaluation were performed. In NF1 patients, 11 (29.3%) had arterial hypertension, 7 (14.6%) had a PHEO. Four (57%) NF1 patients with PHEO were symptomatic at the diagnosis. In PHEO-NF1 patients, we revealed a lower BMI and”


    Neurofibromatosis type 1 (NF1) and pheochromocytoma: prevalence, clinical and cardiovascular aspects.
Zinnamosca L et al.
Arch Dermatol Res. 2011 Jul;303(5):317-25.
  • “Neurofibromatosis Type 1(NF-1) has autosomal dominant inheritance with complete penetrance, variable expression and a high rate of new mutation. Pheochromocytoma occurs in 0.1%-5.7% of patients with NF-1.”


    Pheochromocytoma associated with neurofibromatosis type 1: concepts and current trends
Zografos GN et al.
World Journal of Surgical Oncology 2010, 8:14  
  • “Pheochromocytoma occurs in 0.1%-5.7% of patients with NF-1, and in 20%-50% of NF-1 patients with hypertension, compared to 0.1% of all hypertensive individuals. The mean age at diagnosis of pheochrocytoma in patients with NF-1 is 42 years. Persons with NF-1 are at increased risk for malignant conditions, especially malignant peripheral nerve sheath tumor (MPNST), leukemia and rhabdomyosarcoma.”


    Pheochromocytoma associated with neurofibromatosis type 1: concepts and current trends
Zografos GN et al.
World Journal of Surgical Oncology 2010, 8:14
  • “Pheochromocytoma occurs in 0.1%-5.7% of patients with NF-1, and in 20%-50% of NF-1 patients with hypertension, compared to 0.1% of all hypertensive individuals. The mean age at diagnosis of pheochrocytoma in patients with NF-1 is 42 years. Persons with NF-1 are at increased risk for malignant conditions, especially malignant peripheral nerve sheath tumor (MPNST), leukemia and rhabdomyosarcoma.”

    Pheochromocytoma associated with neurofibromatosis type 1: concepts and current trends
Zografos GN et al.
World Journal of Surgical Oncology 2010, 8:14  
  • Von Hippel-Lindau (VHL) disease, an autosomal dominant syndrome, is clinically subdivided into two types: those without Pheo (VHL type 1) and those with Pheo (VHL type 2). Type 2 VHL disease, where pheochromocytoma develops, accounts for 10% of VHL disease cases. The largest series of VHL patients with pheochromocytomas was described by Walther et al . The mean age at diagnosis was 29.9 year, which was statistically significantly younger than the mean age at diagnosis in a control group of patients with sporadic pheochromocytoma (39.7 years). However, there may be bias due to routine screening in the VHL group.”


    Pheochromocytoma associated with neurofibromatosis type 1: concepts and current trends
Zografos GN et al.
World Journal of Surgical Oncology 2010, 8:14 
  • “ For indeterminate adrenal masses identified at dual-phase IV contrast-enhanced CT, higher enhancement during the arterial phase, arterial phase enhancement levels greater than 110HU, and lesion heterogeneity should prompt consideration of pheochromocytoma.”
    MDCT of Adrenal Masses: Can Dual-Phase Enhancement Patterns Be Used to Differentiate Adenoma and Pheochromocytoma-
    Northcutt BG et al.
    AJR 2013; 201:834-839
  • “ Greater enhancement of pheochromocytomas was variable: 25% greater in the arterial phase, 25% equal across phases, and 50% greater in the venous phase.”
    MDCT of Adrenal Masses: Can Dual-Phase Enhancement Patterns Be Used to Differentiate Adenoma and Pheochromocytoma-
    Northcutt BG et al.
    AJR 2013; 201:834-839
  • “ First, adenomas usually are more enhancing in the venous than in the arterial phase or have equivalent enhancement across phases. Second, a mass that is greater than 110-HU enhancing in the arterial phase, particularly with higher enhancement in the arterial phase, is most likely a pheochromocytoma. Third a pheochromocytoma are more likely to be heterogeneous than are adenomas.”
    MDCT of Adrenal Masses: Can Dual-Phase Enhancement Patterns Be Used to Differentiate Adenoma and Pheochromocytoma-
    Northcutt BG et al.
    AJR 2013; 201:834-839
  • “The differential diagnosis of bilateral adrenal masses include infective aetiologies such as tuberculosis and histoplasmosis; infiltrative disorders such as metastasis from an unknown primary, non-Hodgkin’s lymphoma; amyloidosis and neoplasias such as bilateral pheochromocytoma and adrenocortical carcinoma. Rarely, longstanding untreated congenital adrenal hyperplasia and macronodular adrenal hyperplasia may also be associated with bilateral adrenal masses.”
    Bilateral adrenal masses: varying aetiologies
    Bhansali A et al.
    BMJ Case Reports 2010; doi:10.1136/bcr.10.2009.2347
  • “ A substantial minority of Pheochromocytomas have absolute or relative washout characteristics that overlap with those of lipid poor adenomas.”
    Can Established CT Attenuation and Washout Criteria for Adrenal Adenoma Accurately Exclude Pheochromocytoma-
    Patel J et al.
    AJR 2013; 201:122-127
  • “ In summary a substantial minority of Pheochromocytomas are both homogeneous and show absolute or relative washout profiles that meet established diagnostic criteria for lipid poor adrenal adenomas.”
    Can Established CT Attenuation and Washout Criteria for Adrenal Adenoma Accurately Exclude Pheochromocytoma-
    Patel J et al.
    AJR 2013; 201:122-127
  • “ Pheochromocytomas are often considered the great mimicker of other adrenal tumors. Because of their varied clinical, imaging, and pathologic appearances, accurate diagnosis can be challenging.”
    Pheochromocytoma: The Range of Appearances on Ultrasound, CT, MRI, and Functional Imaging
    Leung K et al.
    AJR 2013; 200:370-378
  • Pheochromocytoma: Facts
    90% are sporadic and 10% are part of syndromes
    - von Hippel-Lindau syndrome (10-26%)
    - MEN Type II (50%)
    - Neurofibromatosis Type 1 (1%)
    - Pheochromocytoma-Paraganglioma Syndromes Associated with SDHB and SDHD Mutation
  • Pheochromocytoma: CT Findings
    - Calcifications are found in 10% of Pheochromocytomas
    - Pheochromocytomas typically are vascular on early phase CT scans
    - Pheochromocytomas can have a 50% washout value and behave just like an adenoma
    - In the absence of metastases it is hard to diagnosis whether or not a Pheochromocytoma is malignant
  • Pheochromocytoma
    - 0.1 – 0.2 % of adults with hypertension
    - “new onset, refractory, paroxysmal or recently exacerbated”
    - Palpitations, headache, diaphoresis, flushing
    - May be asymptomatic
  • CT of Pheochromocytoma
    - Highly variable imaging appearance
    - Homogeneous or heterogeneous
    - May be brightly enhancing
    - Cystic degeneration
    - Calcification in up to 1/3
  • Pheochromocytoma Mimic
    - Renal cell carcinoma metastases
    - Hypervascular
    - Can have central necrosis
    - Can washout like an adenoma
  • Hyperenhancing Adrenals

    In the setting of shock
    -Trauma
    -Sepsis
    -Pancreatitis
    -Hemorrhage induced hypotension

    Poor prognostic indicator
  • Adrenocortical Carcinoma

    1st and 4th decades of life

    55% are functional
    -Cushing syndrome
    -Feminization
    -Virilization
    -Mixed Cushing/virilization

    Hypertension common with functional
  • CT of Pheochromocytoma
    -Highly variable imaging appearance
    -Homogeneous or heterogeneous
    -May be brightly enhancing
    -Cystic degeneration
    -Calcification in up to 1/3
  • Pheochromocytoma: Diagnosis
    24-hour urine to assess for: 
    -Vanillylmandelic acid (VMA)
    -Catecholamines  
    -Metanephrines
  • Pheochromocytoma
    -0.1 – 0.2 % of adults with hypertension
    -“new onset, refractory, paroxysmal or recently exacerbated”
    -Palpitations, headache, diaphoresis, flushing
    -May be asymptomatic
  • Adrenal: Extraadrenal Paragangliomas: CT Findings
    - Homogeneous or heterogeneous hyperenhancing mass
    - Range in size from 1 cm to over 20 cm
    - Common locations are carotid body, jugular foramen, aorticopulmonary region, posterior mediastinum, abdominal paraaortic region including Organ of Zuckerkandl, and pelvis
  • Adrenal: Paraganglioma: Facts

    - Neuroendocrine tumor which arises from the paraganglionic cells
    - Pheochromocytoma is a paraganglioma of the adrenal gland
    - Usually 4th and 5th decades of life
    - 10% are clinically silent and picked up incidentally
  • Adrenal: Paraganglioma: Facts

    - Familial Paragangliomas are 10% of cases
    - 35-50% of familial cases are multicentric
    - Occur with MEN IIA and IIB, tuberous sclerosis, neurofibromatosis, and von Hippel Lindau disease. Also part of Carney’s triad with gastric leiomyosarcoma, chondroma and extraadrenal paraganglioma
  • Adrenal: Paraganglioma "Although paragangliomas can occur in a variety of anatomic locations, the majority are seen in relatively predictable regions of the body." Extraadrenal Paragangliomas of the Body: imaging Features Lee KY et al. AJR 2006; 187:492-504
  • "This case of an incidental pheochromocytoma showing contrast medium washout greater than 50% on delayed imaging reinterates the importance of performing a biochemical profile in any patient with an incidental discovered adrenal mass." Incidental Pheochromocytoma Mimicking Adrenal Adenoma Because of Rapid Contrast Enhancement Loss Yoon JK et al AJR 2006; 187:1309-1311.
  • "Noncontrast 37 HU early phase (60 seconds) 127 HU delayed phase (15 minutes) 62 HU washout 72%" Incidental Pheochromocytoma Mimicking Adrenal Adenoma Because of Rapid Contrast Enhancement Loss Yoon JK et al AJR 2006; 187:1309-1311.
  • Pheochromocytoma: Facts
    - May result in life threatening hypertension or cardiac arrhythmias because of excessive catecholamine secretion
    - Occurs in 0.1-0.9% of hypertensive patients
    - 10% of patients asymptomatic
  • Pheochromocytoma: CT Findings
    - Mass may be solid or cystic
    - Most have attenuation value on noncontrast CT of >10 HU
    - Fat may be seen in a pheo
    - Variable washout curves
  • "On CT, pheochromocytomas may have attenuation values less than 10 HU and also may display more than 60% washout of contrast agents on delayed scanning.Adrenal pheochromocytoma should also be included with adenomas in the differential diagnosis both for masses with low attenuation on unenhanced CT and for lesions exhibiting a high percentage of contrast washout."
    Low-Density Pheochromocytoma on CT: A Mimicker of Adrenal Adenoma Blake MA et al. AJR 2003;181:1663-1668
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