Pulmonary metastasis of intracranial meningioma is rare. We present the cyt
omorphologic features of such a tumor in a 71 yr-old woman who was found to
have multiple lung nodules 13 years following the resection of an atypical
intracranial meningioma. Cytomorphologic features were quite distinct and
included hypercellularity with large syncytial groups of monomorphic cells
with epithelioid morphologic features, often in perivascular arrangements.
Occasional intranuclear cytoplasmic inclusions as well as binucleated cells
with wispy cytoplasmic extensions were also noted. Immunoperoxidase studie
s showed focal positivity for epithelial membrane antigen, The differential
diagnosis includes primary or metastatic adenocarcinoma, malignant mesothe
lioma, and melanoma. Diagn. Cytopathol. 1999;20:291-291. (C) 1999 Wiley-Lis
s, Inc.