Department of Radiology
Tulane University Medical Center
Toshikazu Nambu MD.
Christopher M. Arcement M.D.

Clinical History:

• An incidental finding from an abdominal ultrasound on a 48 year old male revealed an abdominal mass. There were no symptoms or significant medical history that would indicate the presence of this mass.

Radiologic Findings:

• Ultrasonography shows a hypoechogenic, well demarcated mass lesion between IVC and superior mesenteric vein. The mass is mostly homogeneous and there is no sign of calcification. CT; Plain CT demonstrates a homogeneous soft tissue density mass posterior to the liver. Contrast enhanced CT showed enhancement only at the rim of the mass lesion, however dynamic CT demonstrated an acute enhancement of the entire lesion in the arterial phase. Angiography: The mass was hypervascular mass feeded by dorsal pancreatic artery. There was no sign of vascular encasement.

Differential and Final Diagnosis

• Differential Diagnosis:
  Images of this lesion reveal it to be a hypervascular retroperitoneal solid mass without evidence of invasion to adjacent organs. Differential diagnosis includes neurogenic tumor (schwannoma etc.), hemangioma, leiomyoma, plasmacytoma, malignant lymphoma, Castlemans tumor, pheochromocytoma, etc.
• Final Diagnosis:
  Castlemans tumor (hyaline vascular type).

Microscopic section of tumor