CASE 13110 Published on 21.12.2015

An unusual case of synchronous retroperitoneal paraganglioma and adrenal pheochromocytoma

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Scarano AL, Meucci R, Ferrazzoli V, Simonetti G

Rome, Italy;
Email:valentinaferrazzoli@hotmail.it
Patient

67 years, male

Categories
Area of Interest Adrenals ; Imaging Technique CT
Clinical History
A 67-year-old male patient presented at our hospital with intense abdominal pain, nausea and vomiting. He suffered from drug-resistant sustained hypertension and episodic paroxysmal tachycardia. Blood pressure was 165/90 mmHg, heart rate 90 bpm. Blood cells count was normal.
Imaging Findings
The patient was admitted to our Department for a Computed Tomography (CT) examination because his clinical condition was very poor. CT with administration of contrast medium did not show intestinal involvement and/or intraperitoneal fluid. On basal acquisition CT showed a retroperitoneal round, well defined, hypodense lesion (diameter 36 x 32 mm) close to the diaphragmatic right pillar, in proximity to the ipsilateral adrenal gland, showing an apparent cleavage plane from this it. On dynamic acquisition, after administration of contrast medium, mild contrast-enhancement was appreciated during the venous phase. A hypodense nodular lesion (diameter 10 mm) was found close to the lateral side of the left adrenal gland, richly vascularized on dynamic images. These findings, due to their CT features, may be compatible with two synchronous pheochromocytoma lesions: an ectopic lesion cleaved from the right adrenal gland and one at the left adrenal gland.
Discussion
Pheochromocytoma is a neuroendocrine tumour arising from chromaffin cells of the adrenal medulla or extra-adrenal paraganglionic tissue (paraganglioma) [1]. The incidence of the extra-adrenal localization is around 15-20%. Approximately 10% of pheocromocytomas are malignant [2].
Pheochromocytoma is generally characterized by the autonomous production of catecholamines, which are responsible for the clinical manifestations: hypertension, episodes of wide-complex tachycardia, flushing, sweating, headache, nausea and vomiting [3]. Chronically patients with pheochromocytoma can develop a severe and potentially lethal form of dilated cardiomyopathy, which seems to depend on persistently high circulating levels of catecholamines. Thanks to its fat sensitivity, CT has a high accuracy in detecting adrenal lesions. In general pheocromocytomas could have a variable spectrum of imaging appearances, but it is known that almost all of them have attenuation values greater than 10 HU on unenhanced CT. Calcifications are found in approximately 10% of pheochromocytomas. On contrast-enhanced CT examination pheochromocytomas may show homogeneous or variable contrast-enhancement [5], but in some cases these lesions have wash-out characteristics similar to malignant lesions, therefore after 15 minutes, the absolute percentage wash-out is typically less than 60% and the relative percentage wash out is less than 40% [6].
To confirm a radiological diagnosis, biochemical parameters are required to discriminate pheochromocytomas from other hormone-secreting tumours or inactive adenomas. Current guidelines recommend that initial testing must include measurements of plasma and urinary metanephrines, considering that plasma metanephrine and normetanephrine are the best diagnostic tests when respectively >24.5 pg/ml and >219.5 pg/ml [1, 4]. An additional diagnostic test in order to confirm the diagnosis pheochromocytoma is the use of Phentolamine (Regitine), a reversible nonselective alpha-adrenergic antagonist that inhibits the action of catecholamines at the adrenergic receptors, reducing the systolic and diastolic blood pressure respectively more than 35 mmHg and 25 mmHg.
Surgical resection is the first choice treatment, either by open laparotomy or else with a mini-invasive surgery. Laparoscopic or posterior retroperitoneoscopic resection is the preferred procedure in order to provide the clinical remission [7]. If case of unresectable tumours surgical debulking will not improve survival; however, it is occasionally indicated for symptom palliation.
Our patient was treated with posterior retroperitoneoscopic approach in a single-time procedure, in spite of the presence of bilateral lesions. The pathologist confirmed the diagnosis of pheochromocytoma and paraganglioma with a bilateral complete resection.
Differential Diagnosis List
Synchronous retroperitoneal paraganglioma and adrenal pheochromocytoma.
Adrenal adenoma
Adrenocortical carcinoma
Adrenal/extra-adrenal metastasis
Adrenal/extra-adrenal lymphoma
Myelolipoma
Final Diagnosis
Synchronous retroperitoneal paraganglioma and adrenal pheochromocytoma.
Case information
URL: https://www.eurorad.org/case/13110
DOI: 10.1594/EURORAD/CASE.13110
ISSN: 1563-4086
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