Rudimentary cilia in hyperplastic, metaplastic and neoplastic cells of the lung and pleura

Rudimentary cilia are cilium-like processes of the cell usually found within non-ciliated cells. The incidental electron microscopic finding of rudimentary cilia in 10 out 50 cases of hyperplastic, metaplastic and neoplastic lesions of the lung and pleura is reported. The fine structure of these peculiar structures is fully described. Reference is made to their significance and it is suggested that they represent deviations of the differentiation patterns of both normal and neoplastic cells.