Introduction:
Retroperitoneal schwannoma is a rare tumor that originates from the Schwann cells of the peripheral nerve sheath. It is mostly located in the brain and spinal cord, but can affect other untypical places such as the scrotum and penis.

Aim:
The aim of this study was to present two different cases of retroperitoneal schwannoma.

Case study:
The authors present two cases of patients with benign and malignant retroperitoneal schwannomas (malignant peripheral nerve sheath tumor – MPNST).

Results and discussion:
It has been reported that only 0.7% of schwannomas occur in the retroperitoneum. It is difficult to diagnose this tumor preoperatively because of the clinical variety and a lack of the characteristic symptoms. These tumors can mimic different conditions, such as pancreatic tail tumors, a hepatic tumor in the caudate lobe, or lymph node metastases. They can arise at any age, but generally occur between 30 and 50 years of age and develop in any race. Based on the literature published in the last 20 years regarding schwannomas arising in retroperitoneum 20 cases were reported.

Conclusions:
Careful monitoring is highly recommended after retroperitoneal schwannoma removal.