Outer dimensions of the intact cyst or bladder: length 5-15 mm, width 4-12 mm
Thickness of outer wall: up to 80 microns (micrometers), composed of multiple layers
Characteristic features:
(1) protoscolex with 4 suckers and a rostellum
(2) 2 rows of hooklets (13 per row) in the protoscolex
(3) calcareous corpuscles in the parenchyma
Additional findings:
(1) extensively folded (branching) spiral canal
The host response to a dead cyst progresses through the following stages:
(1) subacute to chronic inflammation
(2) foreign body giant cell granuloma
(3) development of a fibrous capsule
(4) fibrotic nodule with patchy calcifications
Immunoperoxidase staining may occasionally be helpful if the diagnosis is in doubt.
