. 2020 Jun 3;27:41. doi: 10.1051/parasite/2020024

Table 1C.

Recommended terms for the clinical aspects of echinococcosis.

Word/expression	Definition	Reasons for acceptance, references, linguistic clarifications	Additional contributor’s opinion, if any
Alveolar echinococcosis, Expression (abbreviation: AE)	Disease due to E. multilocularis, with multiple microcysts giving an “alveolar” aspect on sectioning of the infected organ.	Widely used since the recognition of the disease in the 19th century [18, 78]. From the name of the species “Echinococcus” and the Latin adjective “alveolar”, genitive –alveolaris” (composed of or relating to “alveoli”/small holes/air sacs in the lung). The expression conforms to the recommendation of the WFP; the preceding adjective provides precision on the morphology of the lesion (alveolar). The adjective “alveolar” clearly indicates the morphological aspect of the lesions (especially in the liver).	Recommended by the WHO-IWGE since its first “Guidelines” [83] Differentiates the disease due to E. multilocularis from that due to E. granulosus sensu lato easily.
		Absence of precision regarding the type of disease leads to misunderstanding between experts, stakeholders and policy makers.
^* Anti-parasitic treatment, Expression	Pharmacological or biological treatment of echinococcosis, able to kill Echinococcus spp. or stop or delay their development at the various stages of the parasitic cycle.	May apply to the various stages of Echinococcus spp.-related infections, in the intermediate host (including humans) and in the definitive host (pets, domestic or wild animals). Type of drugs or treatment schedules may be different for the various stages and the various diseases [10, 35, 74, 75].	This expression was unanimously accepted by voters (median: 10) to replace definitively the noun “chemotherapy”, excluding all other options. See also Table 2C.
^* CE cyst, Expression	Anatomical lesion due to infection with Echinococcus granulosus sensu lato, excluding all other species of Echinococcus.	Alternative name to designate a cyst/cysts due to infection with E. granulosus sensu lato. From the abbreviation of “cystic echinococcosis” (CE) and the ancient Greek noun κύστις, -cystis- (anatomical bladder). The expression should be used for clinical cases (cysts observed in cystic echinococcosis in humans or intermediate animal hosts) or in vivo experiments in animals [35, 81]. In agreement with the international WHO-IWGE classification of cysts due to E. granulosus sensu lato infection, from ultrasound examination (CE1 to CE5) [82].	A majority of voters (and a few RRG members) preferred to use “CE cyst” only and reject the use of hydatid cyst (median 8); however, there was no unanimity (3 voters rating under 6). Because the “Biology and Immunology subgroup supported the use of “hydatid” restricted to E. granulosus s.l., at least temporarily, because of the widely used expressions “hydatid cyst” and “hydatid fluid”, both expressions will be tolerated. Using “CE cyst” is highly recommended.
^* Complicated (echinococcosis, CE, AE, cyst…), Adjective	In CE, AE or NE: spontaneous or provoked events (including after therapeutic interventions) that occur in the CE/NE cyst/AE lesion.	Clinical definition. Complications may be: Rupture (outside or in structures of the infected organ), Compression or invasion of internal structures of the infected organ or of neighboring organs, Superinfection of the CE/NT cyst or of the AE pseudo-cyst with bacteria or fungi, Anaphylactic (IgE-dependent allergic) reactions due to echinococcal antigens, Compression or invasion of internal structures/tissues (e.g. for bone or brain) in CE/NE and AE [35].	The adjective “complicated”, for echinococcosis, should not be used to designate the simple growth of the parasite (with or without pain) if there are no consequences on the structures of the infected organ or on the neighboring organs. The large size of the cyst and its proximity to bile ducts or vessels in the liver (or bronchi or vessels in the lung, or vital structures in the brain) are not “per se” complications; even though they make the surgical treatment more difficult or impossible, they are just anatomical particularities.
			The term, with this definition, was accepted unanimously by the voters (median: 10).
Cystectomy, Noun	Removal of a cyst, whatever its nature; more specifically, removal of a CE cyst (anatomical lesion due to the infection by E. granulosus s.l. or E. oligarthra).	From the ancient Greek κύστις, -cystis- (anatomical bladder), and ἐκτομή, -ectomè/ectomia- (to cut out; to cut and remove), the suffix “-ectomy”, in surgical vocabulary, refers to any type of removal of an organ or a lesion. So, literally it means “removal of the cyst”. The context must be clear so that there may be no confusion between a CE cyst and any other types of cysts. In addition, the cystectomy should be qualified by the type of surgical technique, the type of cyst opening, and the extent of cyst removal.	Should never be used alone, without qualification, in a scientific/medical publication. The recommended order for qualification follows the AORC framework: Type of Approach (A): laparotomy, laparoscopy or robotic, Type of cyst Opening (O): opened-cyst (OC) or non-opened cyst (NOC), Type of Resection (R): cystectomy, hepatectomy (segmentectomy, lobectomy or pneumonectomy, for the lung). Completeness of cyst removal (C): total, subtotal or partial. See also Figure 3 for the description of the AORC framework with the definition of its various components in liver CE surgery.
Cystic echinococcosis, Expression (abbreviation: CE)	Disease due to E. granulosus sensu lato.	The expression conforms to the recommendation of the WFP; the preceding adjective, from the Middle French “cystique”, from the ancient Greek κύστις, -cystis- (anatomical bladder), provides precision on the morphology of lesion (cystic).	Recommended by the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) since its first “Guidelines”[83]. Differentiates the disease due to E. granulosus sensu lato, from those due to E. multilocularis, E. oligarthra and E. vogeli, respectively.
Cystic echinococcosis, Expression (abbreviation: CE)	Disease due to E. granulosus sensu lato.	Absence of precision regarding the type of disease leads to misunderstanding between experts, stakeholders and policy makers.
^/* Cystoid, Adjective (Adjective common to “Biology-Immunology” and to “Clinical Aspects”)	Hypodense, cyst-like image observed at CT in AE lesions.	From the ancient Greek eἶδος –eïdos- (shape), the suffix “-id” (with the infix “-o-” whenever useful in a given language) refers to anything “which has the shape of ...something”; thus “cystoid”: which has the shape of a cyst (without being a real cyst).	This adjective was proposed and published for the classification of AE lesions at computed tomography (CT) scanning in 2016 [23] and used thereafter in other publications. Although the adjective “pseudocystic” was preferred by the majority of voters (median: 9 for the “Biology-Immunology group and 7 for the “Clinical Aspects group), the adjective “cystoid” was maintained after the poll to describe cyst-like images observed using computed tomography scanning and which cannot be attributed unequivocally to the necrotic cavity present in advanced lesions of AE.
		In AE, the cystoid structures observed on imaging may be due to the central, liquefied necrosis in advanced AE lesions or to other cyst-like components such as conglomerate of microcysts or in very small lesions, occasionally, a hypodense solid necrosis.
		As these structures do not correspond to a parasitological entity, a specific word should differentiate these pathological cyst-like macroscopic structures from the real parasitic “cysts” of CE.
^* Daughter cyst, Expression	Newly formed hydatids inside (and far less frequently outside, if any) the CE cyst in the development of Echinococcus granulosus s.l. Not applicable to E. multilocularis/AE.	This expression has been in use for a century, translated from the French “vésicule fille” (daughter vesicle), proposed by Dévé (the word “vésicule” being feminine in French, hence “daughter”). It is the established-by-use name of such anatomical structures which are derived from the germinal layer, in case of aggression of the metacestode (see Figs. 2A–2C) [18, 64, 68].	All suggested names for this metacestode structure were rejected by the majority of voters (median for “daughter cyst”, daughter hydatid, and daughter vesicle: 2, 1 and 3, respectively; means 4.63, 1.72 and 4.70, respectively).
^* Daughter cyst, Expression			The word “daughter” evokes sexual reproduction (which does not exist for the metacestode), and “cyst” a complete CE cyst structure, with a fully developed adventitial layer (which is generally hardly present in this structure). However, the adjective “secondary” was considered by the participants in the CRG to be irrelevant for this situation (used for the growth of new cysts after protoscolex spillage), and the noun “vesicle” was accepted by biologists with restricted use for in vitro culture of the metacestode; hence the decision of the SWG to keep the “historical”, albeit inexact, wording.
^* Disseminated (CE or AE, or NE), Adjective	Clinical form of cystic or alveolar or neo-tropical echinococcosis disseminated to more than one organ/tissue.	The definition implies that the cysts/lesions are not in a single organ; it does not assume the nature of dissemination (e.g. multiple location of infection; local/regional invasion; metastasis)	This definition was accepted by the majority of voters (median: 10)
Echinococcosis (plural: Echinococcoses), Noun	Disease(s) related to infection with parasites of the Echinococcus (E.) genus.	Recommended by the World Federation of Parasitologists (WFP) (i.e. name of the genus followed by the suffix -osis) The English name of the World Association of Echinococcosis (WAE; previously “International Association of Hydatidology) was modified in 2015 at the 26th World Congress of Echinococcosis in Bucharest, Romania, to follow this rule.	Without precision regarding the type of disease, this noun can only be used when all diseases due to Echinococcus spp. are considered together, and preferably used as a plural (echinococcoses); it should be avoided in epidemiological, clinical, and mechanistic studies covering all 3 diseases. Besides this “generic” usage, distinction should always be made between cystic echinococcosis (CE), due to E. granulosus sensu lato (s.l.), alveolar echinococcosis (AE), due to E. multilocularis, and neotropical echinococcosis (NE), due to E. vogeli or E. oligarthra.
ERCP, Acronym for Endoscopic Retrograde Cholangio-Pancreatography, Expression	Per-endoscopic technique used to explore the biliary and pancreatic ducts, regardless of the disease; it may or may not be associated with sphincterotomy or other additional procedures.	In CE and AE diagnostic procedures, no exploration of the pancreatic ducts is performed, but the acronym ERCP is commonly used even though the pancreatic exploration is not performed.	Performance of the ERCP may be only for diagnostic purposes; however, usually it has a therapeutic intent and is the first step of perendoscopic biliary drainage. In scientific publications, this distinction should be clearly stated.
Ex-vivo liver resection with auto-transplantation (ELRA), Expression	Surgical operation which includes: Total hepatectomy followed by Ex-vivo resection of the pathological parts of the liver associated with Various types of reconstruction of the bile ducts and/or vessels then by Re-implantation (“auto-transplantation”) of the liver orthotopically.	Surgical technique used for the treatment of advanced AE. The expression includes all steps of the procedure; so it should be preferred to partial expressions such as “ex-vivo liver resection” or “auto-transplantation”. The abbreviation was proposed by the surgical team that has performed most of these procedures and includes all main terms of the expression [2].	The numerous alternative expressions and acronyms should no longer be used.
Hepatectomy	Removal of the liver or part of it.	From the ancient Greek ἧπαρ, -hepar; genitive ἥπατος –hepatos (liver), and the suffix ἐκτομή, -ectomè/ectomia- (to cut out; to cut and remove); in the surgical vocabulary it refers to any type of removal of an organ or a lesion. So, literally it means “removal of the liver” (which is literally correct only in liver transplantation). Various types are described, valid for all types of diseases subject to liver surgery.	Should always be qualified, according to the usual definitions of hepatic surgery, and of the liver segments; definitions are valid for the application to all types of diseases, including echinococcosis [29].
^* Hydatid cyst, Expression (word common to “Biology – Immunology” and to “Clinical aspects”)	Anatomical lesion due to infection with Echinococcus granulosus sensu lato, excluding all other species of Echinococcus.	From the ancient Greek ὑδατίς –hydatis-, genitive – ὑδατίδος -hydatidos (vesicle/bladder full of water). According to the definition of “hydatid” (as an adjective), the expression should be restricted to designate a cyst/cysts due to infection with E. granulosus s.l. in the intermediate host (including humans).	As it adds to confusion in epidemiological and clinical studies, it should never be used to designate the anatomical lesion due to E. multilocularis infection. The definition was approved by the unanimity of voters (median: 10). A majority of voters preferred to totally reject the use of “hydatid cyst” (median 8 for the specific question; see above “CE cyst”). As there was no unanimity and as the “Biology and Immunology” subgroup supported the use of “hydatid” restricted to E. granulosus s.l., at least temporarily, because of the widely used expression “hydatid cyst”, both expressions will be tolerated. Nevertheless, the use of “CE cyst” is highly recommended.
		As it designates an anatomical lesion and not a disease, it should never be used as an alternative name for Echinococcus spp.-related infection (“echinococcosis”). To designate the diseases due to Echinococcus spp. the noun “echinococcosis” qualified by the type of disease (cystic, alveolar or neotropical) should be used (abbreviations CE, AE, NE; see above).
^ Laparoscopy,** Noun	Surgical approach performed for operations in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera.	Qualifies any surgical intervention performed under laparoscopy. To be preferred to “coelioscopy”, more used in gynecology.	Should be added to the noun or expression describing any type of intervention, if this surgical intervention is performed by laparoscopy. See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
^ Laparotomy,** Noun	Surgical approach which includes a large opening of the abdomen.	Qualifies any surgical intervention performed under laparotomy.	Should be added to the noun or expression describing any type of intervention, if this surgical intervention is performed by laparotomy. See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
Modified catheterization technique, Expression Mo-CAT, Acronym	Percutaneous procedure for treatment of CE cysts that results in removal of the cyst layers, possibly including daughter cysts, in addition to the cyst fluid and protoscoleces.	Similar techniques (such as PEVAC) previously described are no longer in use [36, 71, 81]. The name of the procedure and the acronym “Mo-CAT” clearly distinguish this procedure from the conventional PAIR and from the “standard catheterization technique” [3, 61]	The mode of percutaneous puncture guidance (e.g. ultrasound-guided, CT-guided) should also be given, as well as the type/size of catheterization and aspiration.
			The expression and its acronym were accepted by the majority of voters (median: 10).
^* Multicystic (echinococcosis; images), Adjective	Any type of echinococcosis with multiple aggregated cysts observed on imaging or during surgery in the same organ.	Avoids the confusing use of “polycystic”, which currently refers both to cystic or alveolar echinococcosis with multiple large size-cysts observed on imaging, and to E. vogeli infection; also avoids confusion with polycystic liver (and kidney) disease.	The adjective “multicystic” should not be used to qualify the usual “alveolar” aspect of the aggregated “microcysts” in AE. It should not be used to qualify cases of CE or NE with multiple separated and independent cysts observed on imaging or during surgery in the same organ or different organs; see the definition of “multiple cyst-”. This term was accepted by the majority of voters (median: 10). See also “polycystic”, the rejected term, in Table 2C.
^ Multiple cyst-,** Expression used as Adjective	Any type of echinococcosis (except AE) with multiple separated and independent cysts observed on imaging or during surgery in the same organ or different organs.	Clearly distinguishes the “multicystic” aspect of lesions and the presence of multiple cysts.	Should not be used to qualify cases of AE with multiple lesions. Should not be used to qualify cases with aggregated cysts in the same organ (i.e. “multicystic” CE or NE); see the definition of “multicystic”.
Neotropical echinococcoses, Expression (abbreviation: NE)	Diseases due to E. vogeli or E. oligarthra.	Conforms to the recommendation by the WFP (echinococcosis); the preceding adjective provides precision on the particularity of the diseases (neotropical) [36]. “Neotropical” evokes the unique geographic distribution of the Echinococcus spp. involved (in the tropical areas of the New World).	Although the expression does not give any information on the morphology of the lesion (“polycystic” in E. vogeli infection; “unicystic” in E. oligarthra infection), it has been in use for a while in the literature and was approved by the South American Working Group on E. vogeli and E. oligarthra; it usefully distinguishes the diseases caused by these species from CE and AE (see definitions above).
^ New CE cyst(s),** Expression	Appearance of a new CE cyst in a location different from where a CE cyst was diagnosed before.	The definition covers all new cysts that have appeared in a patient after a first diagnosis; the new cyst may have appeared spontaneously (e.g. during a “Watch and Wait” period of follow-up) or after any type of treatment.	This expression was added by the SWG after the poll, in agreement with the writers of the WHO-IWGE Technical Manual. It excludes all cases of cyst recurrence or reactivation, as well as “secondary echinococcosis” (see the definitions of “reactivation” “recurrence”, and secondary echinococcosis” in this Table 1C).
^ Non-opened cyst (total cystectomy),** Expression	Surgical operation which does not include cyst opening before cyst removal (cystectomy). Only applies to CE, and for total cystectomy; it is not relevant for AE.	Linguistically more correct than “close(d) cystectomy” (a cyst can be “non-opened” during the surgical procedure, a cystectomy cannot be close or closed) [81]. This expression clearly describes the situation of the cyst (non-opened) and the highly reduced risk of dissemination of protoscoleces or germinal membrane fragments related to the surgical procedure.	Newly introduced expression, resulting from the discussion between members of the “Clinical aspects” subgroup of the CRG.
^ Non-opened cyst (total cystectomy),** Expression			The adjective expression “non-opened cyst”, its acronym “NOC” and its definition, to qualify more precisely the total cystectomy, were accepted by a majority of voters (median: 10) See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
^ Opened cyst (total, subtotal, partial cystectomy),** Expression OC, Acronym	Surgical operation which includes cyst opening before cyst removal (cystectomy). Only applies to CE; may be at first or second intent; it is not relevant for AE.	Linguistically more correct than “open cystectomy” (a cyst can be opened during the surgical procedure, a cystectomy cannot) [81].	Newly introduced expression, resulting from the discussion between members of the “Clinical aspects” subgroup of the CRG. The adjective expression “opened cyst”, its acronym “OC”, and its definition, to qualify more precisely the total cystectomy, were accepted by a majority of voters (median: 10) See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
		This expression clearly describes the situation of the cyst (opened) and the potential risk of dissemination of protoscoleces or germinal membrane fragments related to the surgical procedure.
(Orthotopic) Liver transplantation, Expression OLT, Acronym	Removal of the recipient’s liver followed by the transplantation of the donor’s liver (or part of liver) at the same anatomical location.	Surgical technique used for the treatment of advanced cases of AE, and more rarely of CE. Often used for “allo-transplantation of the liver”; does not include auto-transplantation.	The adjective “orthotopic” (and its abbreviation “O”) is facultative, since the great majority of liver transplantations in humans are orthotopic.
PAIR, Acronym for Puncture, Aspiration, Injection of protoscolecide, Reaspiration, Expression	Percutaneous treatment of CE cysts using needle puncture and use of protoscolecide agents.	Accepted name and acronym to designate the procedure, since its description by Ben Amor et al., 1986 [8] in French (same acronym), and its first publication in English by Gargouri et al., in 1990 [20]. It describes the 4 steps of the procedure which does not include catheterization of the cyst. The procedure was evaluated and its indications clarified by the WHO-IWGE [10].	The name and acronym must be used only for the initially described procedure, with needle puncture, manual syringe aspiration, without catheterization or other associated techniques.
^* Partial (cystectomy), Adjective	Surgical intervention that only partially removes the 3 layers of the CE cyst.	Opposite to “subtotal” which only leaves parts of the adventitial layer in place, this may include a partial removal of any layer (including parts of the germinal layer and laminated layer); usually only the adventitial layer is left.	By definition, in this situation, the CE cyst has to be opened (first or second intent opening). The adjective and its definition were accepted by a majority of voters (median: 8); however, a complementary discussion was necessary to precisely agree on the differences between “subtotal” and “partial”. See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
^/* Percutaneous pseudocyst drainage, Expression	Imaging-guided percutaneous transhepatic interventional technique used for the drainage of the central “pseudocyst” in advanced lesions of AE. Applies to AE only.	For the treatment of AE, this expression is preferred to “cavity drainage” since it refers to the typical “pseudocyst” resulting from the necrosis of AE lesions; “cavity drainage” is more commonly used for the drainage/treatment of the postoperative cavities after surgery for CE (cystectomy). In AE, such drainage has no temporal relationship with any other interventional treatment.	The expression was accepted by the majority of voters (median: 10). No acronym was fixed. In any description of the procedure, the mode of percutaneous puncture guidance (e.g. ultrasound-guided, CT-guided) should also be given, as well as the type/size of catheterization and aspiration.
^ Percutaneous post-surgery cavity drainage,** Expression	Imaging-guided percutaneous transhepatic interventional technique used for the drainage of post-operative cavities after surgery for CE. Applies to CE only.	A clearly different expression for the drainage of the cystoid necrotic cavity in AE versus the treatment of CE with postoperative residual cavity was considered useful. The “post-surgery” temporal performance of such drainage is clearly indicated in the expression.	This expression was added by the SWG after the poll, after recommendation by the RRG, in order to clearly distinguish the respective situations in AE and CE. In any description of the procedure, the mode of percutaneous puncture guidance (e.g. ultrasound-guided, CT-guided) should also be given, as well as the type/size of catheterization and aspiration.
Perendoscopic biliary drainage Expression	Non-surgical interventional technique used for the drainage of the biliary tree, through ERCP.	The procedure, which applies both to CE and AE, may or may not include biliary stenting [4, 71].	The procedure does not include a curative action on the CE cyst or on the AE lesion; it only treats complications of the diseases and/or of their surgical treatment. In scientific publications, if biliary stenting is associated with the procedure, this should be specifically mentioned, as well as the type, size, and number of stents.
^* Peri-adventitial (cystectomy), Adjective	Total cystectomy performed without opening the cyst, and which uses the dissection space between the adventitial layer and the “normal” liver parenchyma to remove the cyst totally.	The adjective indicates more precisely that the resection is performed outside the adventitial layer (i.e. the adventitial layer is included in the resected cyst) [37, 81].	The use of this adjective for the description of cystectomy is facultative. The adjective “peri-adventitial” and its definition, to qualify more precisely the total cystectomy, were accepted by a majority of voters (median: 10) See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
Protoscolecide, Noun protoscolecidal, Adjective	Compound (natural or chemical) which is able to kill the protoscoleces.	From the ancient Greek “σκὠλεξ”-scolex (worm), genitive: σκὠλεκος -scolecos, and not -scolicos; plural σκὠλεκες, scoleces, and not scolices), with the prefix “πρῶτος”-protos (first/before), and the Latin suffix – “-cide”, from “caedere” (to kill).	Should be used instead of “scolicide”, “scolecide” and “protoscolicide”. See also Table 2C, about the rejected alternative words.
^/* Pseudocyst, Noun, and pseudocystic, Adjective (Noun and Adjective common to “Biology-Immunology” and to “Clinical Aspects”)	Irregular cyst-like anatomical entity due to the central necrosis in AE lesions at advanced stages.	From the ancient Greek “ψευδής” –“pseudès- (= false, deceptive, misleading) that designates something which looks like something but is not; thus “pseudocyst”: anatomical entity which looks like a cyst but is not a cyst. The terms differentiate the cyst-like necrotic cavity in AE from the real “cyst” of CE (with its parasitic structure including the 3 layers). This structure does not correspond to a parasitological entity. In medicine, the term “pseudocyst” is generally used for the necrotic cavities that develop after episodes of pancreatitis in the pancreas.	The terms were approved by the majority of voters (median: 9). The context and the organ being different from pancreatitis, and the formation of the cavity also being due to liquefied necrosis of an inflammatory lesion, it was considered that the words “pseudocyst” and “pseudocystic” could also be used in AE. However, the adjective “cystoid” was maintained to qualify cyst-like structures (irrespective of their anatomical nature) observed at imaging (especially at CT-scan) in AE lesions.
PTBD, Acronym, for Percutaneous Transhepatic Biliary Drainage, Expression	Non-surgical interventional technique used for the drainage of the biliary tree, which is used in AE or complicated CE, after percutaneous puncture.	No synonyms. Expression and acronym widely used in the medical literature, whatever the application. The procedure applies both to CE and AE and does not include a curative action on the CE cyst or on the AE lesion.	The mode of percutaneous puncture guidance (e.g. ultrasound-guided, CT-guided) should also be given, as well as the type/size of catheterization.
^ Reactivation,** Noun	Appearance of daughter cyst(s) in the solid matrix of spontaneously inactivated CE4 cysts that shows an evolution towards a CE3b stage.	The term “reactivation” is reserved for spontaneously inactivated cysts (observed after an initial diagnosis of CE4 cyst, with or without formal “Watch and Wait” follow-up).	This term was added by the SWG after the poll, in agreement with the writers of the WHO-IWGE Technical Manual, in order to clearly distinguish the various situations regarding new lesions or changes in lesions that appeared spontaneously or after attempts at treatment.
^ Recurrence,** Noun	Appearance of an active CE cyst (types CE1-3, usually CE3b) in the same location where a treated cyst was located, independently of the type of previous treatment.	Following its definition in oncology, the term “recurrence” is reserved for the post-therapeutic situation; the term “reactivation” applies to non-treated cysts.	This term was added by the SWG after the poll, in agreement with the writers of the WHO-IWGE Technical Manual, in order to clearly distinguish the various situations regarding new lesions or changes in lesions that appeared spontaneously or after attempts at treatment.
^ Recurrence,** Noun			NB: the occurrence of a post-surgical cavity needs to be excluded before a diagnosis of recurrence is made (cf. the definition of “percutaneous post-surgical cavity drainage”, in this Table 1C).
^ Secondary cyst,** Expression	Newly formed cysts from the dissemination of protoscoleces or germinal layer fragments, in the serosal cavities, spontaneously, accidentally or after surgery or cyst puncture.	Mode of formation distinct from that of daughter cysts; the adjective “secondary” should, however, be restricted to the appearance of new CE cysts in the peritoneum, pleura or meningeal space because of spontaneous or per-treatment spillage of the cyst content.	This expression was added by the SWG after the poll, to clearly distinguish this situation from the development of “daughter cyst”. The expression was approved by the writers of the WHO-IWGE Technical Manual, in order to clearly distinguish the various situations regarding new CE cysts or changes in CE cysts that appeared spontaneously or after attempts at treatment.
^* Standard catheterization (technique), Expression S-CAT, Acronym	Modification of the PAIR technique which includes the insertion of a catheter left or not in the cyst temporarily for the treatment of selected CE cysts.	The name of the procedure and the acronym “S-CAT” clearly distinguish this procedure from the conventional PAIR and from the “modified catheterization technique” (“Mo-CAT”) [3, 35].	The expression and its acronym were accepted unanimously by the voters (median: 10) It was also proposed to complete the description by the following mentions: One-session S-CAT: the catheter is removed during the first procedure; Multiple-session S-CAT: the catheter is removed at another session.
			The mode of percutaneous puncture guidance (e.g. ultrasound-guided, CT-guided) should also be given, as well as the type/size of catheterization.
^/* Sub-total (cystectomy), Adjective	Nearly total cystectomy with incomplete removal of the adventitial layer of a CE cyst	Situation that occurs when limited parts of the cyst cannot be removed safely because of the proximity of blood vessels or other anatomical structures (e.g. bile ducts, bronchi, brain anatomical structures with critical functions). To be qualified of “subtotal”, the cystectomy must remove the totality of the germinal and laminated layer; only limited parts of the adventitial layer are left.	By definition, in this situation (as in “partial cystectomy), the cyst has to be opened (second intent opening). The adjective and its definition were accepted by a majority of voters (median: 10); however, a complementary discussion after the poll was necessary to precisely agree on the differences between “subtotal” and “partial”.
^/* Sub-total (cystectomy), Adjective			See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.
^* Total (cystectomy), Adjective	Complete removal of a CE cyst, including the content (fluid and protoscoleces) and all layers of the cyst (germinal, laminated and adventitial layers.	The adjective “total” insists on the complete removal of the CE cyst by the surgical operation (the “C”, for “completeness” of the AORC framework). It does not prejudge of the opening or not of the cyst at any time of the procedure. This operation, when performed on a non-opened cyst, was sometimes called “peri-cystectomy”; however, a proper definition of the CE cyst is against the use of this word (see Tables 1B and 2C and Figs. 2A–2C).	The adjective “total”, speaking of cystectomy, and its definition were accepted by all voters but one (median: 10). See also Figure 3 and the description of the AORC framework with the definition of its various components in liver CE surgery.

Agreement obtained at the second stage of the consultation (the participants in the Consultation and Rating Group had to rate their approval or rejection of the words/expressions independently on a scale from 0 to 10; whenever relevant, the median of the votes and the nature of the agreement (majority or unanimity) are given in the “Comments” column.

^**

Agreement to recommend a word that was not selected at the first stage of consultation; the approval was obtained at the second stage after further discussion between experts or after recommendation by the RRG.

^*/**

Agreement obtained at the second stage of the consultation; however the final definition was obtained after further discussions with the members of the RRG.