THE STRUCTURE OF ECHINOCOCCAL CYSTS AND HISTOPATHOLOGICAL CHANGES IN LIVER Michal Juszynski Helena Palenga, Danuta Cielecka PhD Department of General Biology and Parasitology Medical University of Warsaw
BACKGROUND The liver is the most common breedingground for Echinococcus granulosus and Echinococcus multilocularis, developing in intermediate host, including human. Growing parasites form single (E.granulosus) or multiple (E.multilocularis) cysts and induce transformation of surrounding liver tissue.
Echinococcosis alveolaris 38 years old male patient
BACKGROUND The extent and type of pathological tissue changes may be significant for effectiveness of surgical intervention and then for consequent therapy of affected liver.
AIM Histological examination of: the parasite tissue and the changes in the liver tissue surrounding the cysts of both types.
MATERIALS Samples of the parasite tissue and of the liver tissue extracted from patients operated in the Clinic of General, Transplantation and Liver Surgery, Medical University in Warsaw
METHODS The samples were fixed in formaldehyde solution, embedded in paraffin, cut into thin shavings and then HE, AZAN, PAS and Whaetley staining were undertaken.
METHODS HE (hematoxillin + eosin), general staining PAS (basic fuchsin) polisacharydes and basal membranes AZAN (azocarmin, orange G, anilin blue) connective tissue Whaetley (chromotrope AR, FCF and SF green), parasite tissue
RESULTS
Echinococcus granulosus CNS (2%) lungs (20%) spleen LIVER (60%) bones
Echinococcus granulosus mature form Strobila in dog s jejunum hooks on the scolex oncosphere - I larval stage ovary
2nd larval stage cerkoid Echinococcus granulosus Development od echinococcal cyst: Oncosphere 0,5-2 hours. Follicular larve 3-6 weeks Protoscolexes appear in larves of diameter 5-20mm after 10 months Fertile Echinococcus alive with protoscolexes Degenerated Echinococcus Calcified Echinococcus /ulceration /scar Human liver Echinococcus isolated from pig s liver
Connective tissue Liver tissue fragments of the laminar layer Degenerated tissues of germinal layer And protoscolexes Echinococcal fluid Echinococcal cyst in liver AZAN
-Dead larve : pacjent 22WS/04 The most important diagnostic features: 2. Hooks 3. Fibrosis layer liver tissue hook Order of necrosis and degeneration changes of parasite tissues in the cyst: 1. Germinal layer and echinococcal fluid 2. Protoscolexes 3. Laminar layer 4. Hooks conjunctive tissue Degenerated parasite s tissue The interior of the cyst consists of fluid and degenerated parasite s tissue AZAN
Echinococcus multilocularis In Poland 20% foxes are infected by Echinococcus multilocularis (2001/2002) Between 1994 and 2006, 42 cases were diagnosed, causing 14 deaths
2nd larval stage - cerkoid Echinococcus multilocularis Liver tissue necrosis Development of the cyst: Oncosphere germinal layer follicular larve development of the follicles (diameter from 1mm to 3 cm) young follicles are alive and include protoscolexes fibrosis older follicles degenerate Echinococcus multilocularis in rodent s liver granuloma laminar layer
Echinococcus multilocularis Fragment of the liver capsule -connective tissue Liver tissue Around parasite s follicles granulomas, there are Resorption granulomas, which form focuses of granulosis Fibrosis: increase in number of conjunctive tissue fibres and degeneration of tissue elements AZAN (azocarmin, orange G, anilin blue)
Inflammational infiltration surrounding resorption granuloma
Echinococcal follicle (red laminar layer) with resorption granulomas PAS
Proliferatig makrophages PAS
Fragment of resorption granuloma giant cells formed from macrophages joining altogether
Laminar layer of parasite follicle (blue) surrounded by necrotic tissue cellular detritus (red). AZAN staining
AZAN
PAS
Multiple follicles of Echinococcus multilocularis green laminar layer. No other parasite tissues inside. Around follicles necrotic tissue: cellular detritus (red) and fibrous connective tissue (green) Whaetley staining
CONCLUSIONS The identification of elements which preserve their structure, even after parasite s death, play a significant role in histological diagnostics of hydatid cysts. In case of E.granulosus such structures are rostellum hooks. In case of E.multilocularis, the laminated layer.
CONCLUSIONS In our research the structures were well visible in AZAN and PAS staining HE staining is not definitive.