Decision Making in Retroperitoneal Nerve Sheath and Nerve-Associated Tumors: A Modular Approach.

Background: Surgical treatment of retroperitoneal nerve and nerve-associated tumors is challenging, especially in cases with large extent. A single surgical access may have limitations and jeopardize patients.

Objective: To present a series of patients to illustrate our individually tailored treatment concept and decision pathway.

Methods: Retrospectively, clinical findings and imaging were related to surgical features and outcome. An algorithm for choice of approach was established.

Results: From 2012 to 2017, we operated on n = 13 patients with retroperitoneal tumors, of these n = 9 were included (n = 6 female, n = 3 male). Histological findings included n = 2 schwannomas, n = 2 malignant peripheral nerve sheath tumors, n = 1 non-origin sarcoma, n = 1 perineurioma, n = 1 intraneural ganglion cyst, n = 1 lymphoma, and n = 1 paraganglioma. In n = 6 patients, we used a monoportal (retroperitoneal/transperitoneal) approach; in n = 2 patients, a biportal retroperitoneal to inguinal/transperitoneal to dorsal approach; and in n = 1 patient, a triportal transperitoneal to dorsal to gluteal approach. In n = 2 patients, we performed an open biopsy only; in n = 2 patients, a tumor enucleation; in n = 3 patients, a subtotal function-sparing resection; in n = 1 patient, a complete resection; and in n = 1 patient, intraneural decompression. In n = 1 patient, a new motor deficit appeared. n = 4 patients required further radio-oncological treatment. n = 8/9 patients are alive without tumor progress or recurrence.

Conclusion: Retroperitoneal nerve or nerve-associated tumors encompass multiple entities. Depending on suspected histology and tumor extension, extensile or combined surgical approaches may be necessary. We present our algorithm for assessment and decision-making regarding surgical access ports and pathways.