Case 51.  Fascioliasis (liver fluke) (65 y-o F)
Surgical specimen of acute cholecystitis
Key words :  Fasciola hepatica, cholecystitis
Large-sized ova are identified in the highly inflamed erosive gallbladder mucosa (HE).   Foreign body reaction against the ovum (pseudotubercle) is formed in the fibrotic gallbladder subserosa (HE).
Cytology specimen of the bile of the same patient
Large-sized ova of Fasciola hepatica are unembryonated and contain yolk cells (Papanicolaou). Compare the size of the ova of F. hepatica with that of C. sinensis. Yolk cells are seen inside the egg, and no miracidium is formed.
  Reference case 51A
Small-sized ova of Clonorchis sinensis seen in the bile contains a miracidium and an operculum (Papanicolaou). Note eosinophilic reaction outside the egg and miracidium formation within the egg. The ovum of C. sinensis is morphologically similar to ova of Metagonimus yokogawai and Heterophyes heterophyes.
Reference case 51B
Surgical specimen of Fasciola hepatica-induced liver abscess (54 y-o F). Irregularly fused abscess is formed in the subcapsular region of the liver. Fasciola hepatica reaches the bile duct via the peritoneum and then the liver parenchyma.
  Reference case 51B
Microscopic features of Fasciola hepatica-induced liver abscess (HE, low power). The viable liver fluke is located in the abscess cavity (HE, low power).
Reference case 51B
Microscopic features of Fasciola hepatica-induced liver abscess (HE, high power). The fluke contains the digestive tract and eosinophilic spiculated cuticles (HE, high power). The spicules are absent from C. sinensis.
  Fasciola hepatica obtained from the gallbladder of the cow (gross features)
Flat flukes measure up to 3 cm, and possess closely situated oral and ventral suckers. Two suckers are seen near the triangular head. The peripheral portion of the fluke is brown-colored. The fluke parasitizes the cow, sheep and goat, and vegetables near the farm are often contaminated with infective metacercaria.
Microscopic features of Fasciola hepatica (HE)
The oral sucker corresponds to the mouth, and the larger-sized ventral sucker is the site of ovulation. The oral sucker is seen in the right side, and the ventral sucker in the middle. Spiral uterine cavity containing ova surrounds the latter.