Case 45.  Actinomycosis of liver (51 y-o F)
Surgically resected liver with yellow-colored, fused liver abscess
Key words :  Actinomyces israelii, liver abscess
The preoperative diagnosis of the liver lesion was inflammatory pseudotumor (gross findings).   Eosinophilic "grains", diagnostic of actinomycosis, are surrounded by neutrophilic infiltration (HE).
The background amorphous substance in the grain, "Splendore-Hoeppli material", is strongly PAS-reactive.   Thin filamentous argyrophilic bacteria are discernible in the grain (Grocott).