Patients

This was designed as a retrospective, bi-center study. The clinical records of all patients seen between June 2006 and June 2017 in two French expert centers for neurofibromatosis and schwannomatosis (Henri-Mondor Hospital in Paris and Larrey Hospital in Toulouse) were reviewed. All patients with a diagnosis of SS were included in the study. The definition of SS was based on the criteria by MacCollin and the modified diagnostic criteria of Baser [5, 6]. Histological analysis was obtained for all patients either after performing a biopsy as a diagnostic procedure or after a surgical intervention for painful lesions. Patients with incomplete data necessary for confirming the diagnosis (no histological analysis, no cerebral MRI and no MRI of the affected area) were excluded. Data were extracted from patients’ clinical records (age of onset, initial presenting symptoms, location of tumors, pain evaluation, ophthalmologic evaluation, quality of life (QOL), genetic data and family history).

Pain was evaluated by using the EVA scale (Pain Comparison Whit Visual Analog Scale: a subjective measure of patient’s pain intensity represented by a point between “0 = No pain at all” and “10 = worst pain imaginable”). QOL was assessed by using the Dermatology Life Quality Index (DLQI: a ten-question questionnaire used to measure the impact of skin disease on the quality of life of an affected person).