An immunohistochemical study of cytokeratin and glial fibrillary acidic protein in chroid plexus papilloma

Abstract

Cellular localization of cytokeratin and glial fibrillary acidic protein (GFAP) was examined in two normal choroid plexuses and five choroid plexus papillomas by the peroxidase-antiperoxidase (PAP) method and double immunofluorescence (IFL) microscopy. Cytokeratin was observed in the majority of epithelial cells in all samples of normal and neoplastic choroid plexuses. On the other hand, GFAP was observed in some of the constituent epithelial cells in two cases of papilloma. Most of these GFAP-positive papilloma cells were simultaneously positive for cytokeratin, as could be seen by the PAP stainings of serial sections and by the double IFL stainings of the same sections. From these findings, it was suggested that normal and neoplastic choroid plexus epithelial cells usually express cytokeratin and that some of the neoplastic cells can simultaneously express both cytokeratin and GFAP.

Papillomas and carcinomas of the choroid plexus: histological and immunohistochemical studies and comparison with normal fetal choroid plexus

“…Also, differently from some reports 19 , laminin was not a helpful tool in the diagnosis of PCA, as it was not detected in any of the 6 cases. All 5 NFCP expressed GFAP, in contrast with previous reports [8][9][10][11]13 . Absence of expression of 35βH11 among all 5 cases of NFCP was similar to what was obtained in CA.…”

“…As most reports in the literature 10,11,13,14,[16][17][18][19]21,31 , GFAP was strongly and widely expressed among all PP and 5/6 PCA, implying, as Rubinstein and Brucher 16 proposed that during neoplastic development choroid plexus epithelial cells express a feature which is the prerogative of glial and ependymal related cells. However in Rubinstein's and other authors' studies [8][9][10][11]13 of normal choroid plexus, there was no glial marker immunodetection, with rare exceptions 14 .…”

“…However in Rubinstein's and other authors' studies [8][9][10][11]13 of normal choroid plexus, there was no glial marker immunodetection, with rare exceptions 14 . Two explanations have been proposed: first, antigen retrieving techniques have been considerably improved compared to a decade ago when most of the reports were published; and second, most of the normal plexus studied were adult samples.…”

“…Choroid plexus cells are truly epithelial in nature as demonstrated by ultrastructural and immunohistochemical studies [6][7][8][9][10][11][12][13][14][15] . Most studies report reactivity to cytokeratins (CK), especially of low molecular weight, vimentin, epithelial membrane antigen (EMA), transthyretin (TTR), S100 protein, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE), but the frequency of reaction varies greatly 6,[9][10][11]13,14,[16][17][18][19][20][21] . In contrast, normal choroid plexus, fetal or adult, has been described as constantly negative to GFAP, with rare exceptions [7][8][9][10][11][12][13][14][15] .…”

“…Most studies report reactivity to cytokeratins (CK), especially of low molecular weight, vimentin, epithelial membrane antigen (EMA), transthyretin (TTR), S100 protein, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE), but the frequency of reaction varies greatly 6,[9][10][11]13,14,[16][17][18][19][20][21] . In contrast, normal choroid plexus, fetal or adult, has been described as constantly negative to GFAP, with rare exceptions [7][8][9][10][11][12][13][14][15] . Poorly differentiated choroid plexus CA, especially in pediatric patients with posterior fossa neoplasms, must be distinguished from other anaplastic tumors with solid diffuse pattern and undifferentiated cells, such as the rare and controversial atypical teratoid / rhabdoid tumor (AT/RT) [22][23][24][25] .…”