Ultrastructural and Histochemical Observations on Serous Ovarian Cystadenomas

Abstract

One hundred and twelve human serous ovarian cystadenomas (46 benign, 33 tumors of borderline malignancy and 33 malignant tumors) were investigated with histological and mucin histochemical methods. EM was applied to 9 benign, 6 borderline and 5 malignant tumors. The epithelium of the benign serous cystadenomas contained ciliated and nonciliated columnar cells, which sometimes were edematous (pale cells) and smaller basal cells. The large Golgi apparatus with small secretory vesicles and occasional larger secretory granules was located in the apical cytoplasm. There were numerous pinocytotic vesicles at the basal plasma membrane. The extracellular mucin in the cystic luman and the mucin on the apical epithelial border consisted of material with vic-glycols (1.2-hydroxyl groups) mixed with sulpho- and carboxymucin. With increasing degree of malignancy the number of ciliated cells diminished and were not found in the malignant epithelium. The number of nucleoli and the amount of carboxymucin with sialic acid residues increased with increasing degree of malignancy. There was no single consistent ultrastructural feature which could be considered as a reliable criterion for malignancy of these tumors in the absence of invasive growth. The findings support the view that serous ovarian cystadenomas are of coelomic origin.