Megapinosome: Morphological Description of a Novel Organelle.

•The megapinosome is a novel endocytic cell organel in macrophages.•The megapinosome is filled with a trabecular meshwork.•The lumen of the megapinosome is connected to the megapinosome complex, a large tubular and cisternal system.•The megapinosome is made visible in the electron microscope using high pressure freezing and STEM tomography.