A. Jouvet et al., STRUCTURAL AND ULTRASTRUCTURAL CHARACTERISTICS OF HUMAN PINEAL-GLAND,AND PINEAL PARENCHYMAL TUMORS, Acta Neuropathologica, 88(4), 1994, pp. 334-348
We have studied 20 pineal parenchymal tumors (PPT) and 4 normal or cys
tic pineal glands both by light and electron microscopy and immunohist
ochemistry with antibodies against glial markers [glial fibrillary aci
dic protein (GFAP) and protein S-100] or neural/neuroendocrine markers
[neurofilaments (NF), synaptophysin and chromogranin A]. Light micros
copy revealed the cellular organization of pinealocytes in the normal
gland and in different morphological types of pineal tumors (typical p
ineocytomas, PPT with intermediate differentiation, mixed PPT exhibiti
ng elements of both pineocytoma and pineoblastoma and pineoblastomas).
Immunohistochemistry showed the presence of GFAP and protein S-100 in
interstitial cells in nonneoplastic pineal gland. Cell processes were
labeled with anti-synaptophysin and anti-NF antibodies. No immunoreac
tivity was found for chromogranin A in non-neoplastic pineal gland. In
pineocytomas, GFAP and protein S-100 were observed in interstitial ce
lls. Synaptophysin and NF were present in the large rosettes of pineoc
ytomas. Synaptophysin, NF and chromogranin A were present in pineocyto
mas with a lobular arrangement of cells. Anti-chromogranin A immunorea
ctivity was also seen in lobular areas of some PPT with intermediate d
ifferentiation. Analysis of normal human pineal gland by electron micr
oscopy showed the presence of vesicle-crowned rodlets (VCR or synaptic
ribbons), fibrous filaments (F), paired twisted filaments but few den
se-core vesicles (DCV) in normal pinealocytes. Tumoral pineal cells ap
peared to differentiate