From the “Hydatid Cyst” to Cystic Echinococcosis: The Impact of History in the Nomenclature
Seance of wednesday 05 april 2017 (L'ÉCHINOCOCCOSE HÉPATIQUE)
DOI number : 10.2699/pyt2-nv31/emem.2017.3.007
Abstract
"Hydatid cyst" is the form of presentation, in the intermediate hosts, of cystic echinococcosis, disease caused by the parasite Echinococcus granulosus sensu lato. In the life cycle of the parasite, the adult worm lives in the intestines of some carnivorous (definitive hosts), and the larva ("metacestode") develops in intermediate hosts, in which humans are accidentally included. "Hydatid cyst" is the name historically given to the larval form, which is best called cystic echinococcosis.
English terminology related to the hydatid cyst and its evolution, as well as certain surgical procedures that are dedicated to it, have incorrect designations, which correspond to bad translations of descriptions, initially in French, and/or incorrect concepts.
A hydatid cyst, as defined by Félix Dévé at the beginning of the last century, is composed of two parts: the parasite, or "hydatid" and the adventitia that surrounding it. The hydatid is a sphere filled with a liquid (of the Greek 'aqueous vesicle') of parasitic origin and composed of two layers (or membranes): the internal, called germinal and the external called laminated. The adventitia is a layer that results from the reaction of the host organ against the parasite. As an integral part of the cyst, the adventitia is therefore a "peri-parasite" or "peri-hydatid" layer, but not a "pericystic" layer, as the term "pericystectomy" implies for the excision of a cyst involving the removal of the adventitia.
Supported by Anglo-Saxon authors, the term "daughter cyst" is also incorrect: it is not the cyst that produces 'daughters', but the parasitic vesicle ... Indeed, in the evolution of a hydatid cyst, the vesiculation of some protoscolex is an attempt to preserve the species; these vesicles do not contain adventitia; they are therefore 'daughter vesicles'.
Terminology is not the only French heritage in the field of echinococcosis: surgical techniques, ultrasound classification of cysts, therapeutic puncture (the 'PAIR'), all come from the francophone medico-surgical tradition.
English terminology related to the hydatid cyst and its evolution, as well as certain surgical procedures that are dedicated to it, have incorrect designations, which correspond to bad translations of descriptions, initially in French, and/or incorrect concepts.
A hydatid cyst, as defined by Félix Dévé at the beginning of the last century, is composed of two parts: the parasite, or "hydatid" and the adventitia that surrounding it. The hydatid is a sphere filled with a liquid (of the Greek 'aqueous vesicle') of parasitic origin and composed of two layers (or membranes): the internal, called germinal and the external called laminated. The adventitia is a layer that results from the reaction of the host organ against the parasite. As an integral part of the cyst, the adventitia is therefore a "peri-parasite" or "peri-hydatid" layer, but not a "pericystic" layer, as the term "pericystectomy" implies for the excision of a cyst involving the removal of the adventitia.
Supported by Anglo-Saxon authors, the term "daughter cyst" is also incorrect: it is not the cyst that produces 'daughters', but the parasitic vesicle ... Indeed, in the evolution of a hydatid cyst, the vesiculation of some protoscolex is an attempt to preserve the species; these vesicles do not contain adventitia; they are therefore 'daughter vesicles'.
Terminology is not the only French heritage in the field of echinococcosis: surgical techniques, ultrasound classification of cysts, therapeutic puncture (the 'PAIR'), all come from the francophone medico-surgical tradition.