DU145 human prostate carcinoma cells are typically poorly differentiated and contain only scantily distributed organelles. However, among numerous tumor cells randomly examined by electron microscopy out of in vitro cultivation, a peculiar, rare oncocyte-like cell type has been observed whose nucleus appears to be of small dimension and with a cytoplasm almost entirely filled with often distorted mitochondria. A few small, dispersed lysosomal bodies, small cisterns of the endoplasmic reticulum and a few glycogen patches can be found among highly osmiophilic contrasted, cytosolic spaces filled by innumerable ribonucleoproteins. The excessive population of mitochondria may have arisen from a more populated tumor cell type wherein the altered mitochondria are found to appear burgeoning into a spherical-like size progeny crowding the tumor cells. Literature cited between 1950 and the present suggests that this rare, oncocytic, benign prostatic tumor cell type is likely appear epigenetically, stemming from an original secretory cell, which is confirmed by the origin of the cell line originally maintained as cell line out of a brain metastatic, adenocarcinoma niche.