For at least three decades I have seen these associations, some more clearly defined, others not so clearly defined (like this example) of mitochondria that show cytoplasmic filaments adjacent, and in very close proximity to the plasmalemma, and to that of an adjacent cell.

This particular mitochondrion (M) is in an alveolar type II cell from a guinea pig lung and the desmosome is very indistinct but still clearly visible and the cell adjacent is very likely an alveolar type I cell due to its thinness.

I reported these in an obscure journal sometime in the 1980s, desmosome-mitochondria-associations as a cursory report, and then never did anything with it.  (aside: I do remember contacting some pathologist for information and to see if he had seen anything like this reported before…three months later, before i finished this paper, i saw his publication on this topic…. i learned a valuable lesson from this, not a negative one, but if one has to protect one’s ideas, then that must show that one doesn’t have that many.. i just accepted this theft).  So now I am returning to many micrographs (about 20k) and gradually finding examples of all the desomosomal – mitochondrial associations like this, to assess the frequency, the reason, and just add some general knowledge on the complex.

Red dot=approximate diameter of a ribosome to translate into 27 nm as a scale marker, M=mitochondrion, the very faint dotted circle has within the increased density between the mitochondrion and the very faint desmosome.  Photo has not been enhanced to show the desmosomal-mitochondrial connection.  10236 M8060 guinea pig alveolar type II cells.