Case 95. Echinococcosis, unilocular (40 y-o M)
Surgical specimen of a large unilocular lung cyst in a Thai adult
Key words : Echinococcus granulosus, lung cyst
A large, thick-walled unilocular cyst is characteristic of infestation of Echinococcus granulosus. The final hosts of this tapeworm are the dog and wolf, and the intermediate hosts are the ruminants and pig.   Protoscolexes are attached to the germinal layer. The cyst wall is not stained by H&E, except for the germinal layer.
Beautiful lamellated structure is demonstrated in the cyst wall by PAS stain.   The beautiful lamellated structure of the cyst wall is also demonstrated by Grocott's silver.
The protoscolex is histologically featured by a chain of hooklets and dispersed calcified spherules.