|This is a low-power photomicrograph of lung tissue containing a large abscess. The center of the abscess contains necrotic debris (1) and there is a rim of viable inflammatory cells (arrows) surrounding this abscess. |
Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
Liquefactive necrosis (or colliquative necrosis) is a type of necrosis which is characteristic of focal bacterial or fungal infections. In liquefactive necrosis, the affected cell is completely digested by hydrolytic enzymes, resulting in a soft, circumscribed lesion consisting of pus and the fluid remains of necrotic tissue. After the removal of cell debris by white blood cells, a fluid filled space is left. It is generally associated with abscess formation and is commonly found in the central nervous system.
For unclear reasons, hypoxic death of cells within the central nervous system also results in liquefactive necrosis.(Brain Infarction => Emollition) This is a process in which lysosomes turn tissues into soup as a result of lysosomal release of digestive enzymes in the face of bacterial onslaught. Loss of tissue architecture means that the tissue is essentially liquefied.
Pathological Findings: Case #1: Lung: Liquefactive necrosis
A 67-year-old male with advanced colon cancer developed obstruction of the bowel and underwent palliative surgery to remove an 8-cm portion of colon containing the obstruction. During the surgery the patient had several episodes of hypotension. After surgery he did not regain consciousness and required ventilator support. Four days after surgery, the patient developed a fever and his white blood cell count was found to be 15,256 cells/cmm. Thus, he was started on broad-spectrum antibiotics. A chest x-ray demonstrated infiltrates in both lungs, which worsened over the next several days. His overall condition continued to deteriorate and he died 12 days after surgery.
At autopsy, metastatic colon cancer was found throughout the abdominal cavity and invading into the liver. The lungs were markedly consolidated and had several focal abscesses that were 2 to 4 cm in diameter. Liquefied material poured out from inside these abscesses when the lungs were sliced.
Images courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
This higher-power photomicrograph of lung demonstrates the edge of the abscess. Note the loss of material from the center of the abscess (1) and loose necrotic material that has not been expelled (2). This material is made up of inflammatory cells (primarily dead white blood cells) and necrotic lung tissue.