Co-existence of neurofibromatosis type 2 and multiple sclerosis: A case report

Non-Optic Glioma-like Lesions in Adult Neurofibromatosis Type 1 Patients

Background/Objectives: Physicians face clinical dilemmas in the diagnosis of non-optic intraparenchymal lesions on MRI brain scans of patients with neurofibromatosis type 1. As the incidence and evolution of these lesions into adulthood remain unclear, we conducted a retrospective study on this topic. Methods: All adult neurofibromatosis type 1 patients who had at least one MRI brain scan in our center were selected for this study. Brain lesions with contrast enhancement after gadolinium administration and/or mass effect were named "glioma-like lesions". Results: In our cohort of 396 adult neurofibromatosis type 1 patients, 182 had at least one MRI scan of the brain. A total of 48 glioma-like lesions were found in 38/182 patients. The majority of glioma-like lesions remained stable, decreased in size or even disappeared during a median follow-up time of 8.5 years. Twelve glioma-like lesions in 11/182 patients were resected or biopsied, and histology showed gliomas of astrocytic origin (WHO grade 1-4). Conclusions: It was concluded from these data that asymptomatic glioma-like lesions on MRI brain scans in neurofibromatosis type 1 patients, either with contrast enhancement and/or mass effect, had an indolent nature. Mildly symptomatic or asymptomatic patients can therefore be followed without invasive diagnostic and therapeutic procedures.

Neurofibromatosis type 2 and multiple sclerosis

Comorbidity of neurofibromatosis type 2 (NF2) and multiple sclerosis (MS) has rarely been reported. Since immunological mechanisms have been implicated in Nf2, coexistence of the two entities may offer insights into schwannoma pathogenesis with respect to the impact of the immune system. We present the case of a woman with a de novo mutation in the NF2 gene who later developed MS. In addition, we found a significantly higher count of T cells in a laryngeal schwannoma of this patient as compared to a schwannoma removed from a NF2 patient without MS. This finding correlated with a higher growth rate in the case of NF+MS.

Recrudescence of herpes virus infections following resection of schwannomas. An antiviral role of merlin?

After schwannoma resection, reactivation of herpes infections were reported. Also, IgM antibody titers against Herpes viri increase among 30% of patients, who develop fascial palsy following schwannoma resection. Merlin interacts with p53 pathway and seems to function as a suppressor of viral propagation. Loss of merlin may increase viral particles in nerve fascicles, yet these may fail to cause infections due to immunostimulation by other aberrant antigens present in schwannoma cells. Removal of schwannomas may decrease the antigenic diversity and trigger viral recrudescence. Understanding the viral etiology - molecular merlin interactions in schwannoma tissues may also help to develop strategies against delayed fascial palsy seen following schwannoma resection.