Serous cystadenoma formation in guinea pig ovaries

Early stages in spontaneous development of serous cystadenomas in ovaries of Hartley strain guinea pigs have been examined by light and electron microscopy. Growth of these cysts from the rete ovarii is apparent as early as 10 days of age. Epithelial cords fill with fluid to form dilated tubules lined with a simple columnar epithelium. While some cells of the rete and early cysts exhibit tufts of cilia, none shows signs of exocrine secretory activity. Examination of the permeability of cystic and noncystic rete to the tracer horseradish peroxidase indicates that tracer can pass through the intercellular space of the epithelium at all stages of development studied. Investigation of three age groups suggests that cystogenesis is a gradual process involving no marked alteration in cell structure.