Pineal parenchymal tumors--utility of immunohistochemical markers in prognostication.
OBJECTIVE
The pineal parenchymal tumors are rare, comprising 15-30% of all tumors of pineal region. Their histological classification alone has been found to be inadequate for prognostication. Hence, we correlated their immunohistochemical profile with the prognosis.


METHODS
A retrospective analysis of 33 pineal parenchymal tumors treated from 1990-2004 was performed. The histological features of the tumors were reviewed and immunohistochemical staining for neurofilament protein (NF), MIB-1, synaptophysin and GFAP were performed. Results were correlated with the patients' survival.


RESULTS
The study comprised 6 pineocytomas (PC), 17 pineoblastomas (PB) and 10 pineal parenchymal tumors with intermediate differentiation (PPT-ID) which included 3 mixed PC/PB. The histological diagnosis was obtained from microsurgical biopsy/decompression, stereotactic or endoscopic biopsy. Adjuvant therapy was advised based on histology. All pineocytomas stained positive for NF. Most pineoblastomas (13/16) failed to show any immunoreactivity with NF. The mean MIB-1 labeling index in pineocytomas, PPT of ID and pineoblastomas were 1.58, 16.1 and 23.52 respectively (p < 0.001). All the tumors stained positive for synaptophysin, although the intensity of the staining varied. NF-positive tumors had a higher chance of disease-free state, irrespective of histological subgroup (p = 0.0036). The median disease-free survival in pineoblastomas with negative NF staining was 5 months, which was less than that of pineoblastomas with positive NF staining (32 months).


CONCLUSIONS
Neurofilament immunoreactivity indicates better prognosis in pineal parenchymal tumors. The MIB-1 labeling index can be utilized as an additional tool to differentiate pineal parenchymal tumors into various subgroups.
Arivazhagan
A
A
Department of Neurosurgery, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
Anandh
B
B
Santosh
V
V
Chandramouli
B A
BA
D000293:Adolescent; D000328:Adult; D000974:Antibodies, Antinuclear / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D008940:Mitotic Index; D016900:Neurofilament Proteins / Q000096:biosynthesis; D010870:Pineal Gland / Q000378:metabolism* / Q000473:pathology*; D010871:Pinealoma / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D016708:Synaptophysin / Q000378:metabolism
D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D005904:Glial Fibrillary Acidic Protein; C440408:MIB-1 antibody; D016900:Neurofilament Proteins; D016708:Synaptophysin