Histopathology of the intraoperative biopsies demonstrated
the presence of multi-loculated cystic structures containing
eosinophilic, fragmented, hyaline membranes that stained
with Periodic acid-Schiff (PAS), necrotic debris, mineralized
granular material, and prominent chronic eosinophilic and
granulomatous inflammation (Figure 2 A,B). No protoscolices
were observed in the tissue sections examined. These findings are
consistent with the metacestode stage of Echinococcus multilocularis.
As a result, formalin-fixed tissue was sent for polymerase
chain reaction (PCR) testing at the Institut für Parasitologie,University of Bern, Switzerland. Sequence data from a PCRgenerated
fragment of the mitochondrial 12S rRNA gene (1),
and restriction fragment length polymorphism analysis of
PCR-generated fragments from the mitochondrial 12S rRNA
and NADH dehydrogenase 1 genes (2) confirmed the identity
of the metacestode as E. multilocularis. The final diagnosis was
hepatic alveolar echinococcosis.