Spinal Schwannomatosis without NF Syndrome: State of the Art

Abstract

Schwannomas are encapsulated and slow grooving benign peripheral nerve tumors. They represent about one third of all benign primary spinal tumors. Most schwannomas occur as isolated lesions, but it could be possible to find a multiple localization involving one or more nerves. The presence of multiple schwannomas in a single patient is suggestive of a genetic predisposition to tumorigenesis and a possible association with syndromes such as neurofibromatosis (NF). Schwannomatosis is defined as an extremely rare tumors syndrome characterized by the presence of multiple schwannomas in the absence of typical signs of NF1 and NF2 syndromes. The genetic and molecular analysis of the tumors, revealed, therefore, that it is possible to frame schwannomatosis as distinct clinical and genetic syndrome. Usually, patients with schwannomatosis develop cranial, spinal or peripheral nerve schwannomas but do not develop vestibular lesions (VS), typical of NF2. Moreover, even the genetic features are different respect to neurofibromatosis, allowing to classify the disease as a distinct nosological entity. The treatment, up to us, in case of symptomatic lesions is surgical removal; in case of asymptomatic lesions is important, instead, to perform serial MRI studies. Moreover, even the genetic features are different respect to neurofibromatosis, allowing to classify the disease as a distinct nosological entity. Furthermore given the high incidence of developing additional lesions in patients with Schwannomatosis, it remains imperative to perform serial brain and spinal cord MRI studies during follow-up time. Important is the differential diagnosis including clinical and radiological criteria plus molecular genetic analysis of tumor cells and lymphocyte DNA. The aim of this editorial is to analyze the state of the art about diagnosis, treatment and follow-up about this extremely rare pathology, often misdiagnosed or confused with other pathologies such as NF syndromes, highlighting the extremely high relevance of molecular genetic study to correctly identify it.