Intraperitoneal dissemination probably caused by needle biopsy of alveolar echinococcosis of the liver: experimental...

Alveolar echinococcosis of the liver (AEL) is a parasitosis with a potential for malignant tumor-like behavior. The disease is diagnosed by a combination of serologic tests, diagnostic images, and the histology of needle biopsy specimens. It remains unresolved whether the biopsy induces subsequent troubles. We designed this study to investigate critical problems after needle biopsy of AEL lesions using an experimental model. Five samples were prepared from the resected lesions of AEL patients: (A) 10% suspension of trypsin digests of the minced lesion; (B) 10% suspension of mesh-filtered sediment of the minced lesion; (C) 10% sediment suspension after washing the nonminced lesion; (D) supernatant after centrifuging intracystic fluid; (E) 10% sediment suspension after centrifuging intracystic fluid. A 1-ml aliquot of each sample was injected intraperitoneally into jirds (gerbils) or cotton rats, respectively. The animals were sacrificed 12 weeks later, and intraperitoneal metacestodes were observed. All samples except D developed metacestodes, and their histologies were all lesions of typical alveolar echinococcosis. These results suggest that a needle biopsy may cause intraperitoneal dissemination or tracial implantation of the parasites along the track of the needle.