An unusual case of schwannomatosis with bilateral maxillary sinus schwannomas and a novel SMARCB1 gene mutation

Abstract

<jats:p>Schwannomas are benign tumors that arise from Schwann cells in the peripheral nervous system. Patients with multiple schwannomas without signs and symptoms of neurofibromatosis Type 1 or 2 have the rare disease schwannomatosis. Tumors in these patients occur along peripheral nerves throughout the body. Mutations of the <jats:italic>SMARCB1</jats:italic> gene have been described as one of the predisposing genetic factors in the development of this disease. This report describes a patient who was observed for 6 years after having undergone removal of 7 schwannomas, including bilateral maxillary sinus schwannomas, a tumor that has not been previously reported. Genetic analysis revealed a novel mutation of c.93G&gt;A in exon 1 of the <jats:italic>SMARCB1</jats:italic> gene.</jats:p>

Hybrid Neurofibroma-Schwannoma

“…The SMARCB1 and LZTR1 gene products are proteins that regulate chromatin conformation and remodeling. The NF2, SMARCB1 and LZTR1 gene loci lie near to each other on chromosome 22, and mutations in SMARCB1 or LZTR1 may lead to conditions that are favorable to somatic alteration of NF2 gene function [ 14 - 15 ].…”

Cystic Schwannoma of the Maxillary Sinus: Clinical and Radiological Findings

“…On the contrary, when these tumors are multiple, they are typically found in Neurofibromatosis type 1, a disease associated to mutation at the NF1 gene [4]. Another form of neurofibromatosis was recently recognized, called schwannomatosis, and a case of bilateral maxillary sinus schwannomas in a patient with this disease was reported very recently in literature [10].…”