Aberrant-type cyst: TEM details of luminal ciliated epithelium. In (a) and (b) slender long apical microvilli are more numerous than cilia. In the cytoplasm numerous irregular vesicles are seen with dense osmophilic content at various degrees of packing. The same cytoplasmic region is rich in mitochondria. Epithelial cells are closely adherent with probable tight junction complexes next to cyst lumen. In (c) a number of spherical vesicles with electron dense homogenous content are interspersed with numerous mitochondria.