Answer for CoW 28 Jan 2018
BILATERAL PHEOCHROMOCYTOMA
Findings
CECT Bilateral adrenal lesions Left adrenal shows central hypodensity Solid areas show contrast enhancement with non enhancing hypodense area in left adrenal – suggestive of necrosis Hypodense non enhancing wedge shaped subcapsular areas in left kidney – suggestive of renal infarct MRI Bilateral adrenal lesions which are hypointense on T1WI and heterogeneously hyperintense on T2WI with central cystic/necrosis in left adrenal No signal drop in opposed phase images Solid components show significant contrast enhancement and diffusion restriction T2 hypointense non enhancing wedge shaped subcapsular areas in left kidney – suggestive of renal infarct
Discussion
Discussion PHEOCHROMOCYTOMA Tumor arising from chromaffin cells of adrenal medulla or sympathetic nervous system Extraadrenal pheochromocytoma: Paraganglioma, Ganglioneuroma Location: Adrenal medulla (90%); extraadrenal (10%) Extraadrenal, along sympathetic chain: Neck, mediastinum, pelvis, or urinary bladder Aortic bifurcation (organ of Zuckerkandl) "Rule of 10s" (or 10% tumor) : 10% extraadrenal (Paragangliomas), 10% bilateral, 10% malignant, 10% extraabdominal, 10% familial, 10% pediatric, 10% silent, 10% have autosomal dominant transmission Associated abnormalities von Hippel-Lindau (VHL) syndrome Neurofibromatosis type 1 Multiple endocrine neoplasia syndromes (MEN) types 2A and 2B Tuberous sclerosis; Sturge-Weber syndrome Carney syndrome Presentation: Symptoms may be episodic or paroxysmal Crisis: Headaches, hypertension, palpitations, sweating, tremors, arrhythmias, pain Classic triad: Headache, palpitations, sweating Atypical: Labile HTN, myocardial infarction, stroke Often clinically silent Lab data 24-hour urine-fractionated metanephrine evaluation Plasma-fractionated metanephrines Ultrasonographic Findings Variable echogenicity: Majority iso- to hypoechoic Intralesional hemorrhage may be echogenic Round and well-circumscribed mass Cystic components NECT Attenuation ranges from low density to soft tissue attenuation Areas of ↑ density (hemorrhage) Areas of ↓ density (cystic degeneration, necrosis) Areas of ↓ density (cystic degeneration, necrosis) Aeas of curvilinear or mural calcification CECT Heterogeneous enhancement due to tissue necrosis, cystic degeneration, hemorrhage Solid components briskly enhance MR Findings T1WI Isointense to muscle and hypointense to liver Heterogeneous signal intensity : Due to areas of hemorrhage and necrosis Areas of increased signal intensity : Due to acute or subacute hemorrhage T2WI Markedly hyperintense ("light bulb") : Due to necrosis, cystic degeneration T2 heterogeneity typical; ↓ T2 signal does not exclude pheochromocytoma DWI : Malignant and benign pheochromocytomas suggested (ADC lower in malignant lesions) T1WI C+ : Can show marked early, as well as prolonged, contrast enhancement Nuclear Medicine Findings I-131 or I-123 metaiodobenzylguanidine (MIBG) MIBG is norepinephrine analogue: Uptake proportional to number of neurosecretory granules within lesion Hybridized MIBG SPECT/CT improves diagnostic accuracy Particularly useful for extraadrenal paraganglioma detection, malignant pheochromocytoma staging DIFFERENTIAL DIAGNOSIS Adrenal Adenoma NECT : Well-defined mass of CECT: Enhancing mass that de-enhances rapidly Adenoma with hemorrhage or necrosis may resemble pheochromocytoma Adrenal Carcinoma Large, unilateral adrenal mass with invasive margins Calcification (30% of cases); variable enhancement Metastatic tumor spread: Lungs, liver, nodes, and bone Inferior vena cava (IVC) tumor thrombus Adrenal metastases Lung, breast, renal cell carcinoma, and melanoma Unilateral or bilateral; central necrosis ― hemorrhage Patient usually known to have malignancy Adrenal lymphoma Usually as part of diffuse disease Rarely limited to adrenals Non-Hodgkin most common; usually bilateral CECT: Mild enhancement (hypovascular) Adrenal Myelolipoma Unilateral fatty adrenal tumor (-100 to -30 HU) T1WI: Typically hyperintense; size varies (2-10 cm) Signal loss at T1WI with fat suppression Adrenal Hemorrhage Etiology: Septicemia, burns, trauma, stress, hypotension and hematological abnormalities CT : Usually bilateral, Recent hemorrhage: ↑ attenuation values MR : Varied signal depending on hematoma age Subacute phase: Usually ↑ signal (methemoglobin) Perilesional dark ring (hemosiderin or ferritin) Adrenal Tuberculosis and Fungal Infection Usually bilateral, heterogeneous, poorly enhancing (acute) Chronic: Small and calcified adrenals
Findings
CECT Bilateral adrenal lesions Left adrenal shows central hypodensity Solid areas show contrast enhancement with non enhancing hypodense area in left adrenal – suggestive of necrosis Hypodense non enhancing wedge shaped subcapsular areas in left kidney – suggestive of renal infarct MRI Bilateral adrenal lesions which are hypointense on T1WI and heterogeneously hyperintense on T2WI with central cystic/necrosis in left adrenal No signal drop in opposed phase images Solid components show significant contrast enhancement and diffusion restriction T2 hypointense non enhancing wedge shaped subcapsular areas in left kidney – suggestive of renal infarct
Discussion
Discussion PHEOCHROMOCYTOMA Tumor arising from chromaffin cells of adrenal medulla or sympathetic nervous system Extraadrenal pheochromocytoma: Paraganglioma, Ganglioneuroma Location: Adrenal medulla (90%); extraadrenal (10%) Extraadrenal, along sympathetic chain: Neck, mediastinum, pelvis, or urinary bladder Aortic bifurcation (organ of Zuckerkandl) "Rule of 10s" (or 10% tumor) : 10% extraadrenal (Paragangliomas), 10% bilateral, 10% malignant, 10% extraabdominal, 10% familial, 10% pediatric, 10% silent, 10% have autosomal dominant transmission Associated abnormalities von Hippel-Lindau (VHL) syndrome Neurofibromatosis type 1 Multiple endocrine neoplasia syndromes (MEN) types 2A and 2B Tuberous sclerosis; Sturge-Weber syndrome Carney syndrome Presentation: Symptoms may be episodic or paroxysmal Crisis: Headaches, hypertension, palpitations, sweating, tremors, arrhythmias, pain Classic triad: Headache, palpitations, sweating Atypical: Labile HTN, myocardial infarction, stroke Often clinically silent Lab data 24-hour urine-fractionated metanephrine evaluation Plasma-fractionated metanephrines Ultrasonographic Findings Variable echogenicity: Majority iso- to hypoechoic Intralesional hemorrhage may be echogenic Round and well-circumscribed mass Cystic components NECT Attenuation ranges from low density to soft tissue attenuation Areas of ↑ density (hemorrhage) Areas of ↓ density (cystic degeneration, necrosis) Areas of ↓ density (cystic degeneration, necrosis) Aeas of curvilinear or mural calcification CECT Heterogeneous enhancement due to tissue necrosis, cystic degeneration, hemorrhage Solid components briskly enhance MR Findings T1WI Isointense to muscle and hypointense to liver Heterogeneous signal intensity : Due to areas of hemorrhage and necrosis Areas of increased signal intensity : Due to acute or subacute hemorrhage T2WI Markedly hyperintense ("light bulb") : Due to necrosis, cystic degeneration T2 heterogeneity typical; ↓ T2 signal does not exclude pheochromocytoma DWI : Malignant and benign pheochromocytomas suggested (ADC lower in malignant lesions) T1WI C+ : Can show marked early, as well as prolonged, contrast enhancement Nuclear Medicine Findings I-131 or I-123 metaiodobenzylguanidine (MIBG) MIBG is norepinephrine analogue: Uptake proportional to number of neurosecretory granules within lesion Hybridized MIBG SPECT/CT improves diagnostic accuracy Particularly useful for extraadrenal paraganglioma detection, malignant pheochromocytoma staging DIFFERENTIAL DIAGNOSIS Adrenal Adenoma NECT : Well-defined mass of CECT: Enhancing mass that de-enhances rapidly Adenoma with hemorrhage or necrosis may resemble pheochromocytoma Adrenal Carcinoma Large, unilateral adrenal mass with invasive margins Calcification (30% of cases); variable enhancement Metastatic tumor spread: Lungs, liver, nodes, and bone Inferior vena cava (IVC) tumor thrombus Adrenal metastases Lung, breast, renal cell carcinoma, and melanoma Unilateral or bilateral; central necrosis ― hemorrhage Patient usually known to have malignancy Adrenal lymphoma Usually as part of diffuse disease Rarely limited to adrenals Non-Hodgkin most common; usually bilateral CECT: Mild enhancement (hypovascular) Adrenal Myelolipoma Unilateral fatty adrenal tumor (-100 to -30 HU) T1WI: Typically hyperintense; size varies (2-10 cm) Signal loss at T1WI with fat suppression Adrenal Hemorrhage Etiology: Septicemia, burns, trauma, stress, hypotension and hematological abnormalities CT : Usually bilateral, Recent hemorrhage: ↑ attenuation values MR : Varied signal depending on hematoma age Subacute phase: Usually ↑ signal (methemoglobin) Perilesional dark ring (hemosiderin or ferritin) Adrenal Tuberculosis and Fungal Infection Usually bilateral, heterogeneous, poorly enhancing (acute) Chronic: Small and calcified adrenals
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!