CASE 11091 Published on 15.12.2014

Extraadrenal pheochromocytoma

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Itsaso Barral Juez1, Idoia Etxegoien Juaristi2, Gurutz Garmendia Larrañaga2

(1) Radiology Department, Hospital Bidasoa, Hondarribia
(2) Radilogy Department, Hospital Donostia, Donostia
Spain
E-mail: itsaso.barraljuez@osakidetza.net
Patient

25 years, female

Categories
Area of Interest Abdomen ; Imaging Technique Ultrasound, CT
Clinical History
25-year-old woman with abdominal pain and sense of right upper quadrant mass.
Elevated chromogranin A (252.8) was detected in blood analysis.
Imaging Findings
A solid abdominal mass with large internal calcifications was detected using ultrasound. A CT revealed the mass, located adjacent to the lower pole of the right kidney, dilation of the excretory system of the kidney secondary to compression of the mass (there was no tumour involvement of the ureter in histological diagnosis). This retroperitoneal mass presents calcifications and necrosis areas. It was difficult to determine in which organ it had its origin.
CT also detected a liver mass (left lobe), two implants, one in the hepatic hilum and another in the right adnexal area, all of them suggestive of metastases.
The radiological suspicion diagnosis before surgery was renal tumour, retroperitoneal sarcoma and extraadrenal pheochromocytoma.
Treatment included surgery (resection of the mass and liver lesion, right nephrectomy, hepatic hilar lymphadenectomy) and posterior chemotherapy. Two years after diagnosis, the disease is stable.
Discussion
Pheochromocytoma is a rare adrenal tumour with a wide spectrum of imaging appearances and many clinical manifestations. More than 90% are located in the adrenal glands. Extraadrenal pheochromocytomas develop in paraganglionic chromaffin tissue of the sympathetic system. Common locations are the organ of Zuckerkandl, bladder wall, retroperitoneum, heart, mediastinum and carotid and glomus jugulare bodies [3].
These tumours secrete catecholamines that can induce life-threatening hypertensive crises or cardiac arrhythmias. Patients may be asymptomatic and in such patients masses tend to be larger than hyperfunctioning tumours. The classic clinical manifestations are hypertension, headaches and diaphoresis. To confirm the diagnosis, biochemical markers and imaging are necessary.
Pheochromocytomas can be bilateral and malignant in 10% of patients [3]. The diagnosis of malignant pheochromocytoma on imaging is very difficult in the absence of metastatic disease [1].
Pheochromocytomas can be diagnosed with a variety of modalities: CT, MRI, radionuclide imaging and, rarely, ultrasound.
CT: pheochromocytomas can be solid, cystic complex masses, homogeneous, heterogeneous, may have calcifications and fat. Most of them have attenuation higher than 10HU, but some pheochromocytomas could be incorrectly categorized as adenomas. They typically enhance avidly but can be heterogeneous and contain cystic areas. The wash-out rate in malignant lesions is less than 40% [3].
MRI: pheochromocytoma appearance is a mass with low signal intensity at T1-weighted imaging and with high signal intensity at T2-weighted imaging. Commonly it enhances avidly at T1-weighted imaging after administration of gadolinium. However, the appearance can be different and the tumours may present low signal intensity at T2-weighted imaging, therefore they can be wrongly characterized as adenomas [2].
Radionuclide imaging: is useful when clinically suspected pheochromocytoma cannot be localized, to confirm that a mass is a pheochromocytoma or to exclude metastatic disease [2].
The preferred treatment option of pheochromocytoma is laparoscopic adrenalectomy. Extraadrenal pheochromocytomas may require other surgeries depending on the location of the tumour. Symptomatic treatment includes alfa-adrenergic blockade and calcium channel antagonist. In patients with metastatic pheochromocytoma, treatment combining surgery, chemotherapy and I-MIBG (metaiodobenzylguanidine) radiation therapy has been shown to increase the survival rate [1].
Prognosis is poor for patients with malignant pheochromocytoma (54% 5-year survival rate).
Prognosis is favourable for patients with benign pheochromocytoma [1].
Pheochromocytomas are rare tumours that may be considered the great mimicker of adrenal tumours, are often clinically silent and the imaging appearances are varied (usually solid, may appear as fatty, cystic or calcified masses).
Differential Diagnosis List
Extraadrenal pheochromocytoma
Renal carcinoma
Retroperitoneal sarcoma
Final Diagnosis
Extraadrenal pheochromocytoma
Case information
URL: https://www.eurorad.org/case/11091
DOI: 10.1594/EURORAD/CASE.11091
ISSN: 1563-4086