Fig. 2

Microscopic appearance of lungs and mesenteric lymph nodes tissue. a Severe fibrin exudation in the interstitium and in alveolar lumina (arrows). Diffuse mixed inflammatory infiltrate of the interalveolar septa by lymphocytes, histiocytes, and scattered neutrophils. HE. Bar, 100 µm. b Necrosis of interalveolar septa with accumulation of eosinophilic and karyorrhectic debris (arrow) and type II pneumocyte hyperplasia (asterisk). Alveolar macrophages with intracytoplasmatic numerous basophilic structures morphologically consistent with T. gondii tachyzoites (arrowhead). HE. Bar, 50 µm. c Necrosis of lymphoid tissue (asterisk) and focus of the neutrophilic inflammatory infiltrate (arrow). Scattered macrophages with intracytoplasmatic T. gondii tachyzoites (arrowhead). HE. Bar, 25 µm