Pheochromocytomas are rare catecholamine-producing neuroendocrine tumors that are usually benign, but which may also present or develop into a malignancy.
Malignant pheochromocytomas are tumours accounting for 10% [1] of all pheochromocytomas. Predicting such behavior is notoriously difficult.
We report our experience about two women who had malignant pheochromocytomas to evaluate our management.
Case 1:
33 years old women with no specific illness, admitted for exploration of paroxystic abdominal pain occurring since two weeks associate with waves of nausea, in a context of loss of weight and asthenia. The clinical exam found a painful mobile hard right iliac mass with no fever or troubles of blood pressure or pulse. Abdominal ultrasound (US) showed a 4,6 * 3,9 cm retroperitoneal mass with area of decreased echogenicity well circumscribed, near to the iliac vessels with compression of the right ureter inducing a moderate hydronephrosis at the right side. Computed tomography (CT) showed a retroperitoneal 5 x 4 cm tissular mass at the inferior pole of the right kidney, the injection of contrast product showed area of necrosis in the center of the mass. The mass was front of the inferior cava vein, the vein was free; the mass pushed the duodena to the right side. No adenopathy or ascitis were found.
Abdominal M.R.I: showed double structure retroperitoneal mass, with hypersignal at T2 on the periphery of the mass and heterogenic hyposignal at the center of the mass. This mass compress the inferior cava vein and she had contact with the antero-lateral and right side of the upper mesenteric artery, this mass compress the right ureter inducing a ureteral dilatation (fig 1)

Figure 1 : Abdominal MRI retroperitoneal mass with hypersignal at T2 on the periphery and heterogenic hyposignal at the center



Biological and biochemical markers were normal. Surgical treatment of this mass by an open laparotomy was proposed, and a resection of the tumor was made. The follow up was simple, and the results of the histological exam conclude to a malignant pheochromocytoma.
Case 2:
A20 years old woman with no specific antecedent was admitted for exploration of acute abdominal pain of the right side of the abdomen without vomiting or other symptoms, in a context of loss of weight and asthenia. The clinical exam found a painful mobile hard mass of the right iliac area, no other elements were found at the clinical exam.
Abdominal Ultrasound (US) found a 6,5 x 5,5 cm paravertebral, tissular, retroperitoneal mass with area of decreased echogenicity, pushing back the inferior cavae vein.
Abdominal Computed tomography (CT) showed a tissular well circumscribed mass, this mass was about 7,8x5,8x4,8 cm, It was localisated at the paraverterbral right side, this mass was well vascularized, and she was pusching back the inferior cava vein (fig 2).

Figure 2 : Abdominal CT: right paraverterbral mass well vascularized, and pusching the inferior cave vein.



Abdominal M.R.I showed a tissular paravertebral mass, well vascularized front of the inferior cava vein, at the level of the inferior edge of the right kidney with a capsule which had a low density, this mass became opaque after the injection of Gadolinium.
The surgical exploration found a mass accoled to the duodenum, the aorta, and the inferior cava vein (fig 3), the dissection of this mass was so hard that we decide to associate a vascular reconstruction of the inferior cava vein (fig4).
The follow up was normal and the result of the histological exam conclude to a malignant pheochromocytoma.

Figure 3 : operative finding: a mass accoled to the duodena, the aorte, and the inferior cavae vein



Figure 4 : Vascular reconstruction of the inferior cava vein



Conclusion
Malignant pheochromocytoma continues to present considerable diagnostic and management problems. Surgical treatment could be expeditiously performed for patients with a correct pre-operative diagnosis and adequate pharmacological preparation. This approach of both adrenal and extraadrenal pheochromocytoma can be accomplished safely and with relatively few serious complications.

• The diagnosis and management of malignant pheochromocytoma and paraganglioma Alexandra Endocrine-Related Cancer (2007).