Peripheral nerve sheath tumors of the upper extremity and hand in patients with neurofibromatosis type 1: topography of tumors and evaluation of surgical treatment in 62 patients

Objective: Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome with a tendency to develop peripheral nerve sheath tumors (PNST). Plexiform neurofibromas (PNF) are detected in a high proportion of affected patients. The tumors can lead to severe disfigurement and are classified as precancerous. This study examines the surgical procedures that have been performed on large PNST of the upper limb and hand, and investigates whether a specific distribution pattern of the tumors can be detected in surgically treated cases. Methods: Surgical procedures on the upper extremity and hand performed on patients with NF1 were evaluated at an interval of 25 years (1992-2016). Topography of the tumors was classified according to dermatomes. The number of interventions per patient, duration of operations, and complications of the interventions were registered. An overview of the surgical treatment of PNST of the upper limb and hand was obtained from the literature, with special consideration of the genetic background of treated tumors. Results: One hundred and sixty-three surgical interventions on the upper limb and hand were performed in 62 patients with NF1 for the treatment of large PNST, predominantly PNF (age: mean value: 27.33 years, male: 33, female: 29; right side: 25, left side: 26, bilateral: 7). Surgical procedures lasted an average of 72.47 minutes. In approximately half of the patients, one surgical procedure was sufficient. Duration of stay in hospital was on average 7-11 days. Neurological complications were rarely noted and occurred only temporarily. There were no dermatomes affected by PNF with particular frequency. However, some dermatomes were more often simultaneously affected by a PNF at the same time as others. Conclusion: Although the distribution pattern shows some accumulation of tumor localization, tumors are distributed evenly and show very variable size and extent in individual cases. Surgical treatment of PNF of the upper limb and hand helps alleviate the physical discomfort that these patients have from their disfiguring disease. Repeated interventions are necessary relatively often in order to adapt the tumorous region to the outline of the limb and to improve its function.