The morphology of the earliest invasive cell in low genital tract epidermoid neoplasia.

The light and electron microscopic characteristics of the distinct eosinophilic microinvasive cell in the lower genital tract epidermoid neoplasia are described. The eosinophilic quality of the invasive cell is associated with an accumulation of contractive protein seen at the ultrastructural level. The presence of these differentiated cells near the basement membrane should be viewed with more concern as they contain the cytoplasmic machinery with which to invade.