Analysis of pituitary oncocytoma

Ultrastructural changes of 30 cases of pituitary adenomas were observed and comparative study about mitochondrial changes in 12 cases of hypofunction,11 cases of acromegaly and 7 cases of amenorrhea was carried out. Clusters of plenty of mitocondria were found in 50% cases of hypofunction,in which two cases showed mitocondria with apparently abnormal shape and concentric inclusion bodies;a great many of deformed and vacuolar mitocondria were presented in 27.2% cases of acromegaly,No increase of mitocondria was present in the group of amenorrhea. Whenever there was an increase of mitocondria,the secretory granules in cytoplasm were either scanty or absent.In the cells with deformed mitocondria,there were shrinkage of nuclei, aggregation of chromatin,rim-formation around the nuclei and a lot of lysosomes and lipofuscins. Because the oncocytes occured not only in the nonfunctional pituitary adenoma,but also in the normal parotid thyroid,parathyroid and other kinds of tumors,so oncocytoma should not be considered an independent disease entity.