TITLE:
Ki-67 immunohistochemical expression in mandibular ameloblastoma: A prognostic indicator for local recurrence
AUTHORS:
Ayman Hegab, Mohmmad Shuman, Mohammed Abd El-Akher, Delaram Arwlan
KEYWORDS:
Mandibular Ameloblastoma; Recurrence; Immunohistochemistry; Ki-67
JOURNAL NAME:
Open Journal of Stomatology,
Vol.3 No.9,
December
25,
2013
ABSTRACT: Objective: This study used Ki-67
to evaluate the proliferative activity of ameloblastoma in an attempt to provide
a scientific basis for any differences in the biologic behaviour that exists
between the different types of ameloblastoma and correlate the results with the
recurrence rate. Study design: We assessed Ki-67 expression by
immunohistochemistry in 32 cases of mandibular ameloblastoma. Formalin-fixed,
paraffinembedded blocks were sectioned and used for Haematoxylin & Eosin
(H&E) staining. H&E slides were used to re-evaluate the histological types
of the ameloblastoma. Immunohistochemical analysis for Ki-67 with a labelled
streptavidin-biotin-peroxidase complex technique was performed on tumour
sections using Monoclonal Mouse Anti-Human Ki-67 Antigen (clones MIB1, code
M7240, Dako Corporation). Lymph nodes (lymphoma) were used as positive control
for Ki-67. Results: The specimens comprised 18 cases of Follicular
ameloblastoma, 7 cases of Cystic ameloblastoma, 4 cases of plexiform
ameloblastoma, and 3 cases of Acanthotic ameloblastoma. The results showed
that cellular proliferative activity varied within the ameloblastoma types.
There was no statistically significant difference in the Ki-67 Acanthotic,
cystic and follicular types of ameloblastoma, while plexiform type showed statistically significantly higher levels
than the other 3 types. The mean Ki-67 labelling index of plexiform
ameloblastoma ranged from 13 to 30 with a mean of 19.75. The mean values of Ki-67
were statistically significantly higher in recurrent thannon-recurrent
cases. Conclusion: The significant expression of Ki-67 could provide useful
prognostic markers for proliferative activity and good prognostic indicators
for recurrence rate of mandibular ameloblastoma.