ECTOMESENCHYMAL CHONDROMYXOID TUMOR OF THE ANTERIOR TONGUE - 19 CASESOF A NEW CLINICOPATHOLOGICAL ENTITY

We present 19 cases of a previously undescribed myxoid tumor of the an terior tongue. These lesions occurred in nine women and 10 men aged 9 to 78 years (median, 32 years). Most tumors were seen as slow growing, painless nodules in the anterior dorsal tongue. The duration of growt h ranged from a few months to 10 years. All tumors were treated by sur gical excision, and two recurred. Microscopically, they exhibited a lo bular proliferation of ovoid and fusiform cells, which often had multi lobated nuclei and occasional foci of atypia, in a chondromyxoid backg round. Some tumors entrapped muscle or nerve fibers and had a tendency for blunt infiltration of adjacent tissue, The cells were diffusely a nd intensely immunoreactive for glial fibrillary acidic protein (GFAP) and cytokeratin but were decorated less frequently with antibodies fo r smooth muscle actin and S-100 protein. Reactivity for epithelial mem brane antigen and desmin was not found. We believe these tumors fail t o meet established clinicopathologic criteria for any existing myxoid neoplasms of the tongue, including nerve sheath myxoma, myoepithelioma , benign mixed tumor, ossifying fibromyxoid tumor of soft parts, extra skeletal myxoid chondrosarcoma, and glial and chondroid choristomas or heterotopias. Although the histogenesis of this neoplasm is unclear, we suspect that a cell of undifferentiated ectomesenchyme is the proge nitor and suggest the descriptive term ectomesenchymal chondromyxoid t umor (ECT) of the anterior tongue be adopted.