Ectomesenchymal chondromyxoid tumour of the anterior tongue.

Ectomesenchymal chondromyxoid tumour (ECT) of the anterior tongue was first described in 1995. To date, only 23 cases have been reported in the literature. Two new cases of ECT have been described, with immunohistochemical analysis including cytokeratin (CK) profile, GFAP, S-100 protein, SMA, CD-57, EMA, desmin and Ki67. Tumour cells showed intense and diffuse staining for GFAP and diffuse staining for S-100 protein. Pan-keratin, high- and low-molecular-weight CK, CK 7, 8, 18, 19 and 20 were negative. Tumour cells were also negative for desmin, SMA, CD-57 and EMA. Ki67 was positive in only scattered cells. The findings of the present study support the suggested ectomesenchymal origin for ECT, rather than myoepithelial salivary gland origin. The low Ki67 expression is in agreement with the low growth rate, small size and lack of mitotic activity in the present cases, as well as in those previously described.