Six year natural progression of a clinically monitored retroperitoneal schwannoma: A case report

Introduction and importance: Schwannomas arise from Schwann cells, which make up the neural sheath of peripheral nerves. These tumors are usually seen in the head, neck and flexor surfaces, but can arise in the retroperitoneal space on rare occasions. This case gives the unique opportunity to watch the long term progression and speed of growth of this rare tumor and the development of symptoms over time.

Case presentation: Here, we describe the interesting case of a retroperitoneal Schwannoma discovered incidentally that was then monitored over the course of six years. After the tumor grew from 2.4 × 2.2 cm to 5.4 × 5.2 cm over this time, symptoms such as abdominal pain, nausea, constipation, increased urinary frequency, and left leg paresthesia arose, prompting for removal of the tumor. On follow-up two weeks later, the patient reported resolution of symptoms.

Clinical discussion: Treatment for this tumor is either immediate excision or the "watch and wait" method, as this tumor has a low rate of malignant transformation. The tumor discussed in this case had a higher rate of growth before removal when compared to other studies examining retroperitoneal Schwannoma development.

Conclusion: The "watch and wait" method of treatment for this benign tumor is effective, but it is important to ensure the patient is aware that the tumor will likely continue to grow. Given this, the patient should be informed of possible mass effect symptoms to monitor for.