Intramitochondrial rodlet-like inclusions in human leukemic lymphocytes.

Some mitochondria in leukemic cells in two of nine investigated patients with chronic lymphocytic leukemia and in one patient with morphologically less usual form of this disease contained unusual rodlet-like inclusion bodies. These structures were always present in the matrix of frequently dilatated intercristal spaces. The width of rodlet-like inclusions ranged between 10 and 20 nm, their maximal length was 114 nm. All observed rodlet-like inclusion bodies appeared to be composed of fine filaments 2...3 nm in width and resembled the DNA containing structures in mitochondria of few other cell types. In mitochondria of leukemic cells, however, these inclusions represent a further structural abnormality.