Tumors of the Peripheral Nervous System

Abstract

Tumors of the peripheral nervous system come in different histopathologies. The current WHO classification includes neurofibromas, invasive growing plexiform neurofibromas, schwannomas, cellular schwannomas, perineuromas and malignant peripheral nerve sheath tumors. They are frequent tumors and occur spontaneously as well as hereditary, i. e., as part of hereditary tumor diseases. Neurofibromas, invasive growing plexiform neurofibromas and malignant peripheral nerve sheath tumors are part of neurofibromatosis type 1 (NF1). Schwannomas, and cellular schwannomas are part of neurofibromatosis type 2 (NF2). NF1 and NF2 are prototypic diseases caused by mutation in genes coding for tumor suppressors. They are genetically well defined. These hereditary tumor diseases of the peripheral nervous system are characterized by childhood occurrence of tumors and multiplicity of tumors. In addition other tumors, especially of the central nervous system and non-tumorous pathology are found in these diseases. Until now surgery was the main therapy in these diseases. However, recent research using animal models and human in vitro models is the basis for the hope to find pharmacological molecular targets to treat these diseases. In NF2 many patients in addition suffer from general disease of the peripheral nervous system, presenting as polyneuropathy. In NF1 this is found only in few patients. Examples for tumors of the peripheral nervous system, their clinical presentation, radiological appearance and pathophysiology will be demonstrated.