Brief report on similar mutational changes in neurofibromatosis type 2 gene in minute pulmonary meningothelial-like nodule and meningioma of the central nervous system

Abstract

Introduction: Minute Pulmonary Meningothelial-like Nodules (MPMNs) are usually detected incidentally adjacent to lung cancer tissue. The pathogenesis is unknown. MPMNs reportedly share the status of neurofibromatosis (NF)-2 gene with meningiomas of the central nervous system.

Results: Immunohistochemical staining of two MPMNs revealed they were positive for epithelial membrane antigen (EMA), vimentin, CD56, and progesterone. We identified deletion of the NF-2 gene in two MPMNs and one CNS meningioma.

Conclusions: MPMN and CNS meningioma may develop via the same mechanism through NF-2 translocation. Further studies are required to elucidate the genetic similarities between these entities.

Methods: We used fluorescence in situ hybridization to explore the status of the NF-2 gene in MPMNs and compare it with that of CNS meningiomas. We used a commercially available locus-specific probe for the NF-2 region to analyze whole tissue sections of two MPMNs and two CNS meningiomas by fluorescence in situ hybridization.

Keywords: fluorescence in situ hybridization; immunohistochemistry; meningioma of central nervous system; minute pulmonary meningothelial-like nodule; neurofibromatosis-2 gene.

Figure 1. FISH analysis showing deletion of NF-2 gene in an MPMN

(A) Loss of one red and one green signal in >50% of tumor cells was interpreted as deletion of 22q. Normal amounts of 22q (two red NF2 and two green CEN22q signals in >50% of nuclei) are also shown (B).