At autopsy of a patient who died of acute rheumatic fever, the visceral pericardium is covered by a shaggy layer of red-brown material likened to butter spread on bread. Microscopy shows an exudate composed largely of strands of polymerized fibrin with scattered neutrophils. What type of acute inflammation does this represent?

• A Serous inflammation
• B Fibrinous inflammation ✓
• C Purulent (suppurative) inflammation
• D Catarrhal inflammation

Explanation

Severe increase in vascular permeability allowed fibrinogen-rich fluid to escape into the pericardial space, where it polymerized into the grossly shaggy fibrin coat described as bread-and-butter pericarditis, defining fibrinous inflammation. Purulent inflammation requires pus dominated by neutrophils, as in bacterial empyema. Serous exudate is protein-poor, typical of blister fluid, and catarrhal describes mucus-rich mucosal inflammation.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.