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Pulmonary meningothelial-like nodules: a genotypic comparison with meningiomas

Diana N Ionescu1, Eizaburo Sasatomi, Dalal Aldeeb

  • 1Department of Pathology, Division of Anatomic Pathology, University of Pittsburgh Medical Center, Presbyterian University Hospital, Room A610, 200 Lothrop St., Pittsburgh, PA 15213, USA. ionescudn@msx.upmc.edu

The American Journal of Surgical Pathology
|March 27, 2004
PubMed
Abstract

Insights

Minute pulmonary meningothelial-like nodules (MPMNs) appear reactive, lacking the genetic damage seen in meningiomas (MGs). MPMN-omatosis syndrome may indicate a transition toward neoplastic growth.

Area of Science:

  • Pulmonary pathology
  • Molecular genetics
  • Oncology

Background:

  • Minute pulmonary meningothelial-like nodules (MPMNs) are incidental findings in the lungs.
  • MPMNs share histological and immunohistochemical similarities with meningiomas (MGs).

Purpose of the Study:

  • To investigate the genetic similarities and differences between MPMNs and MGs.
  • To determine the potential origin and progression of MPMNs.

Main Methods:

  • Studied 33 MPMNs and 10 MGs using immunohistochemistry.
  • Performed mutational analyses on microdissected tissue with 20 microsatellite markers across 11 genomic regions.

Main Results:

  • MPMNs showed high vimentin expression but lacked cytokeratin and synaptophysin.
  • Loss of heterozygosity (LOH) was found in 25% of single MPMNs and 33.3% in MPMN-omatosis syndrome.
  • MGs exhibited frequent LOH at specific genomic loci (22q, 14q, 1p) not observed in MPMNs.

Conclusions:

  • Isolated MPMNs appear to have a reactive origin due to a lack of mutational damage.
  • MPMN-omatosis syndrome may represent a stage between reactive and neoplastic proliferation.
  • MPMNs and MGs are distinct based on key molecular genetic events.

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