The specimen is a slice of lung tissue showing a laminated thromboembolus ("blood clot") obstructing the pulmonary artery branch that supplies the lower lobe. As a consequence, there is a wedge-shaped, haemorrhagic (blood-filled) zone of infarcted ("dead") tissue in the lower lobe, with the apex of the wedge at the site of the vessel blockage. The hilar lymph nodes and pleura are heavily stained with carbon, consistent with the patient's history of heavy smoking.