2012 年 10 巻 4 号 p. 336-343
An immunohistochemical study of oral carcinoma cuniculatum (CC) was performed to clarify the factors that contribute to the unique cuniculatum architecture. Sixteen lingual specimens, consisting of six CC, six conventional squamous cell carcinoma (SCC) and four verrucous carcinoma (VC), were studied. From the immunohistochemical findings, cytokeratin 10 and cytokeratin 13 showed greater positive expression in the prickle layer of CC than conventional SCC and VC. Gene-related p53, Ki-67, and p63 revealed low immunopositive rates in CC and high positive rates in the basal layer of conventional SCC and VC. These results suggested that the tumor cells of CC were well-differentiated with low proliferative activity. Regarding cell-cell adhesion molecules, laminin 5γ2 was revealed strongly in the basal layer of CC, with thinner and discontinuous distribution in conventional SCC. Although E-cadherin was negative or weakly positive in conventional SCC and VC, it was remarkable in the prickle and basal layers of CC compared with the other two lesions. It was supposed that cell-cell adhesion molecules participate in the construction of the unique architecture of CC. From these results and a review of the literature, independent branching crypts such as the rabbit caves of CC could be formed by the restriction of invasiveness and migration by the comparatively firm cell-cell linkage and low proliferative activity of tumor cells.
