Hydatid disease, abdominal dissemination

Case contributed by Liz Silverstone


Abdominal pain following blunt trauma two weeks ago. Persistent RUQ pain. Urinary frequency.

Patient Data

Age: 25 years
Gender: Female

Large hepatic cysts contain barely perceptible thin internal membranes.
Elongated inferior protrusion indicates a likely site of rupture. Moderate ascites.
Large pelvic cyst superior to the bladder which was surgically removed.

6 month follow up


The more superior hepatic cyst is smaller, the irregular bilobular inferior cyst is stable in size and contains floating membranes, (waterlily sign).
Interval thickening of the intracystic membranes. 
The pelvic cyst has been removed.
Minimal pelvic free fluid.

Case Discussion

Imaging of her chest and brain was negative for extra-abdominal dissemination.

Surgical excision of the pelvic cyst and debridement of the abdominal wall:
Microscopic Description:

Specimen 1: Pelvic cyst. The sections show hydatid cyst, characterized by a laminated, acellular cyst wall containing a fibrinous inflammatory exudate with abundant neutrophils. Protoscolices are present within the specimen. No viable tissue is included in the specimen.

Specimen 2: Anterior abdominal wall. The sections show hydatid cyst, with features as described above (Specimen 1). No protoscolices are seen; a single refractile hooklet is present within the inflammatory exudate. No viable tissue is included in the specimen.

The waterlily sign of detached membranes is regarded as a transitional stage between active and inactive hydatid disease.

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