Abstract
Ameloblastoma is a locally invasive odontogenic tumor with a high recurrence rate. Its local invasiveness is aided by angiogenesis, which can be correctly estimated by CD34. On the other hand, maspin decreases the local invasive and metastatic capability of cancer cells and functions as an angiogenesis inhibitor. We aim to assess the association between maspin expression and microvessel density in ameloblastoma. Twenty-five formalin-fixed paraffin-embedded (FFPE) blocks of ameloblastoma cases were prepared for antibody processing to CD34 and maspin. Positive immunohistochemical staining was marked by brown cytoplasmic/membrane coloration for CD34 and by nuclear/cytoplasmic coloration for maspin. At the x40 magnification, we counted blood vessels in two areas of dimension; 300 x 400 mu m (area A) and 150 x 200 mu m (area B) adjacent to the tumor region to assess relative dispersion of the vessels bordering the tumor. The overall approximate microvessel density (MVD) for area A = 11 (minimum 2, maximum 21) and that for area B = 5 (minimum 1, maximum 10). The MVD in the area A of plexiform ameloblastoma was similar to that of the unicystic, while the hemangiomatous variant had the highest MVD for area A. Maspin positivity was present only in the cytoplasm of ameloblast, stellate reticulum, and the fibrous connective tissue in varying proportions. There was no evidence of the anti-angiogenesis effect of maspin in ameloblastoma from this study. The significance of cytoplasmic localization of maspin in the ameloblasts and stellate reticulum cells needs further investigation.