Gross pathology photograph of the membrane and hydatid daughter cysts excised from a human lung.

Hydatid disease is a parasitic infestation by a tapeworm of the genus Echinococcus. Endemic areas usually involve third world countries. The liver is the most common organ involved, followed by the lungs.

source: http://phil.cdc.gov/phil_images/20030113/3/PHIL_2865_lores.jpg

This file is a work of the Centers for Disease Control and Prevention, part of the United States Department of Health and Human Services, taken or made as part of an employee's official duties. As a work of the U.S. federal government, the file is in the public domain.