Inflammatory pseudotumor of the retroperitoneum removed via a retroperitoneoscopic approach

Abstract

Background: Inflammatory pseudotumors were mostly encountered in the lung. Retroperitoneal inflammatory pseudotumors are relatively rare. Although laparoscopic surgery with a modified flank position is widely performed for retroperitoneal tumors, we placed the patient in the supine position to maintain the normal anatomical view of the retroperitoneal space. We report a case of retroperitoneal inflammatory pseudotumor extracted via retroperitoneoscopic surgery in the supine position.

Methods and results: A 53-year-old man presented with back pain and frequent urination. Ultrasonographic examination revealed a solid tumor above the urinary bladder. This tumor was diagnosed as a primary retroperitoneal tumor by computed tomography, magnetic resonance imaging, and angiography. The retroperitoneoscopic procedure was adopted to remove this tumor. Histopathologic examination revealed an inflammatory pseudotumor. There was no evidence of recurrence 5 years after surgery.

Conclusions: The diagnosis of the inflammatory pseudotumor is rarely made before histologic examination. Only pathologic examination allows the correct diagnosis. Consequently, most patients undergo surgical treatment. A recurrence rate of 25% has been reported for inflammatory pseudotumors. Thus, radical resection is needed. The retroperitoneal laparoscopic approach with the patient in the supine position is useful for surgically treating these primary retroperitoneal tumors located below the level of the renal vessels.

Figure 1.

MRI revealed low signal intensity on unenhanced T1-weighted images (A), while high intensity on unenhanced T2-weighted images showed a well-defined mass (B).

Figure 2.

Three ports were inserted at the right lower abdomen (A). Prior to removal of the tumor, great vessels including the vena cava and bilateral common iliac artery were exposed (B).

Figure 3.

The tumor was well capsulated macroscopically (A). Microscopically, the tumor was composed of diffuse proliferation lymphocytes without nuclear atypia, as well as myofibroblast cells and fibroblast cells (B).