European Journal of Molecular & Clinical Medicine

Abstract

AIM: To asses and compare the histopathological parameters and biological markers like β-
catenin, N- cadherinand Calbindin in medulloblastoma (MB) subtypes.
MATERIAL and METHODS: This retrospective comparative study includes 54 formalin
fixed paraffin embedded tumor tissue samplesbetween January 2003 and December 2010.
MB was first examined using standard histological preparations.Subsequently,
immunohistochemistry was performed using antibody against β- Catenin, N-cadherin and
Calbindin.
RESULTS: Themean age in the pediatric age group was 10.7 years and 33 years in adult
witha male preponderance.Majority of classic MB were of midline vermian origin (74%) in
contrast to the lateral location of desmoplastic MB (69%) (P=0.001).Most common
histological subtype was classic (61%). Apoptosis was more commonly present in
desmoplastic MB(43%).24% of MB showed the presence of necrosis,mostly in MB with
extensive nodularity subtype. Perivascular pseudo-rosette and Homer-Wright rosette
formation was observed in 65% of MB as in all age group.59% showed moderate anaplasia
followed by mild (30%). All four anaplastic subtypes showed severe anaplasia.β-catenin
immunoreactivity was observed in 17 (31%) of the 54 MB. Of the 17 positive cases, 12
(71%) were of classic phenotype.Expression of N-Cadherin (strong nuclear as well as
cytoplasmic) was observed in 42 (78%).Only 6 cases showed focal cytoplasmic positivity for
calbindin.