[Annulate lamellae of in vitro cultivated squamous epithelial cancer cell lines].

Annulate lamellae have been described in rapidly dividing and proliferating cells as germ cells of invertebrates and vertebrates and in some neoplastic cells. Although their functional significance is still unknown, it is postulated that these organelles play a central role in cell growth and differentiation. In the present study, annulate lamellae have been documented for the first time in cultured recloned squamous cell carcinoma of the head and neck, which had not been subjected to prior chemical treatment. The stacks of annulate lamellae are frequently in continuity with cisterns of the rough endoplasmatic reticulum.