they kind of look like bloated histiocytes Image

brain gross Image

or this, or both Image

this is the lung on the patient Image

Acanthamoeba species usually act as opportunistic pathogens in immunocompromised individuals causing pneumonitis or skin ulcers. From these lesions the amebas can then spread to the brain resulting in insidious frequently fatal encephalitis called "granulomatous amebic encephaliti"s.

In healthy individuals, Acanthamoeba can cause an ulcerating keratitis, which has been associated with using improperly sterilized contact lenses.

The organisms are found worldwide in soil and fresh and salt water. They may contaminate not only contact lens solution but have been found in physiotherapy pools, air-conditioning units, etc.

Photos courtesy of Dr. Jeffrey Myers, University of Michigan.