IgG4 overexpression is rare in meningiomas with a prominent inflammatory component: a review of 16 cases.
Meningiomas with prominent inflammation are traditionally classified as "lymphoplasmacyte-rich meningioma" (LPM). Both inflammatory and neoplastic meningeal proliferations have recently been linked to IgG4 disease, although a potential association with LPM has not been previously explored. Sixteen meningiomas with inflammatory cells outnumbering tumor cells were further characterized by CD3, CD20, CD68 and/or CD163, CD138, kappa, lambda, IgG and IgG4 immunostains. There were 11 female and 4 male patients, ranging from 22 to 78 (median 59) years of age. Tumors consisted of 10 World Health Organization (WHO) grade I, 5 grade II and 1 grade III LPMs. Immunohistochemically, the most numerous cell type was the macrophage in all cases followed by CD3-positive T cells and fewer CD20-positive B cells. Plasma cells ranged from moderate-marked (N = 5) to rare (N = 7), or absent (N = 4). Maximal numbers of IgG4 plasma cells per high power field (HPF) ranged from 0 to 32, with only two cases having counts exceeding 10/HPF. The IgG4/IgG ratio was increased focally in only two cases (30% and 31%). Additionally, plasma cells represented only a minor component in most examples, whereas macrophages predominated, suggesting that "inflammation-rich meningioma" may be a more accurate term. The inflammatory stimulus for most cases remains to be elucidated.
Department of Pathology, University of California San Francisco, San Francisco, CA.
Aseem
A
Lal
Sonika
S
Dahiya
Michael
M
Gonzales
Annie
A
Hiniker
Richard
R
Prayson
Bette K
BK
Kleinschmidt-DeMasters
Arie
A
Perry
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008577:Meningeal Neoplasms / Q000276:immunology* / Q000473:pathology; D008579:Meningioma / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D060787:Neoplasm Grading; D055815:Young Adult
D007074:Immunoglobulin G
IgG4; inflammation; lymphoplasmacyte rich; meningioma