Adrenal Gland Pheochromocytoma

Case example

Igniting adrenal gland

A 10 year-old, male, mixed breed dog was an acute abdomen.

CT findings

A large heterogeneously soft tissue attenuating mass is within the right retroperitoneal space causing a mass-effect with caudoventral deviation of the ipsilateral kidney (image 1). A normal right adrenal gland is not seen. Active bleeding into the large non-enhancing component of the mass, characterized by amorphous and rounded, severely contrast enhancing areas is evident on the post i.v. contrast administration images (image set 2). A moderately and heterogeneously enhancing extension from this mass enters the lumen of the abdominal caudal vena cava, causing near complete luminal narrowing (image 3 and 4). A moderate to large amount of effusion extends throughout the left and more so right retroperitoneal space, characterized by homogenously fluid attenuating and non-contrast enhancing material (image 5).


  • Malignant soft tissue neoplasm of the right adrenal gland with caudal vena caval invasion and malignant thrombus formation, as well as secondary luminal stenosis and moderate to large volume retroperitoneal haemorrhage and haematoma formation. A pheochromocytoma would be considered.

Learning points

  • Pheochromocytomas are more prone to vascular invasion and the CT findings of vascular invasion have a good agreement with surgical/necropsy findings.
  • Pheochormocytomas tend to have a higher Houndsfield Unit (HU of approximately 44) in comparison to other adrenal gland neoplasms (HU of approximately 28). However, given the overlap in pathologic features between the tumor types still limits the potential for tumor type distinction by CT.

More information

  • »Comparison of Computed Tomographic and pathologic findings 17 dogs with primary adrenal neoplasia«
    — Gregori et al., Vet Radiol Ultrasound: 2014; 56(2):153-159
  • »Adrenal mass imaging with multidetector CT: pathologic conditions, pearls, and pitfalls«
    — Johnson et al., Radiographics. 2009; 29: 11333-1351
  • »Contrast-enhanced computed tomography as a preoperative indicator of vascular invasion from adrenal masses in dogs«
    — Schultz et al., Vet Radiol Ultrasound. 2009; 50: 625-629

Images courtesy of Vetos Tierklinik Berlin, Valera medizinisches Kleintierzentrum Berlin, Germany.