diff --git a/src/components/map-projects/AdvancedSettings.jsx b/src/components/map-projects/AdvancedSettings.jsx
index e5f7f05..a12d37e 100644
--- a/src/components/map-projects/AdvancedSettings.jsx
+++ b/src/components/map-projects/AdvancedSettings.jsx
@@ -3,21 +3,24 @@ import { useTranslation } from 'react-i18next'
 import TextField from '@mui/material/TextField'
 import Collapse from '@mui/material/Collapse'
 import Button from '@mui/material/Button'
+import FormControlLabel from '@mui/material/FormControlLabel'
+import Checkbox from '@mui/material/Checkbox'
+import FormHelperText from '@mui/material/FormHelperText'
 import UpIcon from '@mui/icons-material/ArrowDropUp';
 import DownIcon from '@mui/icons-material/ArrowDropDown';
 
 
-const AdvancedSettings = ({ namespaceValue, setNamespace, defaultNamespace }) => {
+const AdvancedSettings = ({ namespaceValue, setNamespace, defaultNamespace, isCoreUser, useLexicalVariants, setUseLexicalVariants }) => {
   const { t } = useTranslation()
   const [open, setOpen] = React.useState(false)
 
   return (
     <div className='col-xs-12 padding-0' style={{marginBottom: '16px', marginTop: '4px'}}>
-        <Button size='small' variant='text' color={open ? 'primary' : 'secondary'} endIcon={open ? <UpIcon fontSize='inherit' /> : <DownIcon fontSize='inherit' />} onClick={() => setOpen(!open)} sx={{textTransform: 'none'}}>
-          {t('map_project.advanced_settings')}
-        </Button>
+      <Button size='small' variant='text' color={open ? 'primary' : 'secondary'} endIcon={open ? <UpIcon fontSize='inherit' /> : <DownIcon fontSize='inherit' />} onClick={() => setOpen(!open)} sx={{textTransform: 'none'}}>
+        {t('map_project.advanced_settings')}
+      </Button>
       <Collapse in={open}>
-    <div className='col-xs-12 padding-0' style={{marginTop: '4px'}}>
+        <div className='col-xs-12 padding-0' style={{marginTop: '4px'}}>
           <TextField
             fullWidth
             size='small'
@@ -31,6 +34,23 @@ const AdvancedSettings = ({ namespaceValue, setNamespace, defaultNamespace }) =>
               defaultValue: 'Namespace passed to $resolveReference. When blank, defaults to {{owner}}. Drives which URL Registry entries apply when resolving canonical URLs.'
             })}
           />
+          {
+            isCoreUser &&
+              <>
+                <FormControlLabel
+                  sx={{marginTop: '8px'}}
+                  control={
+                    <Checkbox
+                      size='small'
+                      checked={Boolean(useLexicalVariants)}
+                      onChange={event => setUseLexicalVariants(event.target.checked)}
+                    />
+                  }
+                  label={t('map_project.use_lexical_variants')}
+                />
+                <FormHelperText sx={{marginTop: 0}}>{t('map_project.use_lexical_variants_description')}</FormHelperText>
+              </>
+          }
         </div>
       </Collapse>
     </div>
diff --git a/src/components/map-projects/ConfigurationForm.jsx b/src/components/map-projects/ConfigurationForm.jsx
index 3661541..c358a20 100644
--- a/src/components/map-projects/ConfigurationForm.jsx
+++ b/src/components/map-projects/ConfigurationForm.jsx
@@ -58,7 +58,7 @@ const VisuallyHiddenInput = styled('input')({
 
 const deriveCanonicalUrl = relativeUrl => relativeUrl ? `https://ns.openconceptlab.org${relativeUrl}` : ''
 
-const ConfigurationForm = ({ project, handleFileUpload, file, owner, setOwner, name, setName, description, setDescription, repo, onRepoChange, repoVersion, setRepoVersion, versions, mappedSources, targetSourcesFromRows, algosSelected, setAlgosSelected, sx, algos, validColumns, columns, isValidColumnValue, updateColumn, configure, setConfigure, columnVisibilityModel, setColumnVisibilityModel, onSave, isSaving, candidatesScore, onScoreChange, includeDefaultFilter, setIncludeDefaultFilter, filters, setFilters, locales, isLoadingLocales, setAIAssistantColumns, AIAssistantColumns, inAIAssistantGroup, lookupConfig, setLookupConfig, encoderModel, setEncoderModel, isCoreUser, canBridge, canScispacy, promptTemplates, promptTemplate, onPromptTemplateChange, AIModels, AIModel, setAIModel, namespace, setNamespace, promptOutputLocale, setPromptOutputLocale }) => {
+const ConfigurationForm = ({ project, handleFileUpload, file, owner, setOwner, name, setName, description, setDescription, repo, onRepoChange, repoVersion, setRepoVersion, versions, mappedSources, targetSourcesFromRows, algosSelected, setAlgosSelected, sx, algos, validColumns, columns, isValidColumnValue, updateColumn, configure, setConfigure, columnVisibilityModel, setColumnVisibilityModel, onSave, isSaving, candidatesScore, onScoreChange, includeDefaultFilter, setIncludeDefaultFilter, filters, setFilters, locales, isLoadingLocales, setAIAssistantColumns, AIAssistantColumns, inAIAssistantGroup, lookupConfig, setLookupConfig, encoderModel, setEncoderModel, isCoreUser, canBridge, canScispacy, promptTemplates, promptTemplate, onPromptTemplateChange, AIModels, AIModel, setAIModel, namespace, setNamespace, promptOutputLocale, setPromptOutputLocale, useLexicalVariants, setUseLexicalVariants }) => {
   const { t } = useTranslation();
   const isLLMAlgoNotAllowed = !repoVersion?.match_algorithms?.includes('llm')
   const appliedLocales = filters?.locale ? filters?.locale?.split(',') : []
@@ -308,7 +308,7 @@ const ConfigurationForm = ({ project, handleFileUpload, file, owner, setOwner, n
       <LookupConfig value={lookupConfig} onChange={setLookupConfig}/>
       {
         setNamespace &&
-          <AdvancedSettings namespaceValue={namespaceValue} setNamespace={setNamespace} defaultNamespace={defaultNamespace} />
+          <AdvancedSettings namespaceValue={namespaceValue} setNamespace={setNamespace} defaultNamespace={defaultNamespace} isCoreUser={isCoreUser} useLexicalVariants={useLexicalVariants} setUseLexicalVariants={setUseLexicalVariants} />
       }
       {
         inAIAssistantGroup && isCoreUser && promptTemplates?.length > 0 &&
diff --git a/src/components/map-projects/MapProject.jsx b/src/components/map-projects/MapProject.jsx
index 1153d87..e53c2b6 100644
--- a/src/components/map-projects/MapProject.jsx
+++ b/src/components/map-projects/MapProject.jsx
@@ -248,6 +248,7 @@ const MapProject = () => {
   const [lookupConfig, setLookupConfig] = React.useState({})
   const [encoderModel, setEncoderModel] = React.useState(DEFAULT_ENCODER_MODEL)
   const [promptOutputLocale, setPromptOutputLocale] = React.useState(null)
+  const [useLexicalVariants, setUseLexicalVariants] = React.useState(false)
   // Project canonical-resolution context (plans/unified-mapper-model.md
   // "Project configuration: explicit canonical context"). Empty = use the
   // project owner as the default resolution namespace.
@@ -555,6 +556,7 @@ const MapProject = () => {
       setRetired(Boolean(copiedProject.include_retired || false))
       setAlgosSelected(copiedProject.algorithms || [])
       setEncoderModel(copiedProject.encoder_model || DEFAULT_ENCODER_MODEL)
+      setUseLexicalVariants(Boolean(copiedProject.use_lexical_variants))
       if(copiedProject.target_repo_url) {
         const repoParams = URIToParentParams(copiedProject.target_repo_url, true)
         fetchRepo(dropVersion(copiedProject.target_repo_url))
@@ -747,6 +749,7 @@ const MapProject = () => {
       setEncoderModel(response.data?.encoder_model || DEFAULT_ENCODER_MODEL)
       setProjectPromptTemplateKey(response.data?.prompt_template_key || '')
       setPromptOutputLocale(response.data?.prompt_output_locale || null)
+      setUseLexicalVariants(Boolean(response.data?.use_lexical_variants))
       setAnalysis(response.data?.analysis || {})
       setProject(response.data)
       setConfigure(false)
@@ -1216,6 +1219,7 @@ const MapProject = () => {
     formData.append('filters', JSON.stringify(getFilters()))
     formData.append('prompt_template_key', getProjectPromptTemplateKey())
     formData.append('prompt_output_locale', promptOutputLocale || '')
+    formData.append('use_lexical_variants', useLexicalVariants)
     const isUpdate = Boolean(project?.id)
     let service = APIService.new().overrideURL(owner).appendToUrl('map-projects/')
     if(isUpdate)
@@ -1328,7 +1332,8 @@ const MapProject = () => {
         'source': _repo.short_code || _repo.id
       },
       map_config: getMapConfigs(),
-      filter: rows.length > 1 ? getFilters() : getFacetQueryParam(isEmpty(_filters) ? appliedFacets[rows[0].__index] : _filters)
+      filter: rows.length > 1 ? getFilters() : getFacetQueryParam(isEmpty(_filters) ? appliedFacets[rows[0].__index] : _filters),
+      variants: useLexicalVariants
     }
   }
 
@@ -3948,6 +3953,8 @@ const MapProject = () => {
       setPromptOutputLocale={setPromptOutputLocale}
       namespace={namespace}
       setNamespace={setNamespace}
+      useLexicalVariants={useLexicalVariants}
+      setUseLexicalVariants={setUseLexicalVariants}
     />
   )
 
diff --git a/src/i18n/locales/en/translations.json b/src/i18n/locales/en/translations.json
index 2d4b869..47daad3 100644
--- a/src/i18n/locales/en/translations.json
+++ b/src/i18n/locales/en/translations.json
@@ -626,7 +626,9 @@
     "create_similar": "Create similar",
     "create_similar_name": "Copy of {{name}}",
     "set_ai_assistant_output_language": "Set AI Assistant output language",
-    "ai_assistant_output_locale": "Output locale"
+    "ai_assistant_output_locale": "Output locale",
+    "use_lexical_variants": "Use Lexical Variants",
+    "use_lexical_variants_description": "Expand $match search to include English spelling variants (e.g. color/colour, leukemia/leukaemia) when matching concept names."
   },
   "app": {
     "web_version": "Web Version",
diff --git a/src/i18n/locales/es/translations.json b/src/i18n/locales/es/translations.json
index 066a5bd..ec8d6a1 100644
--- a/src/i18n/locales/es/translations.json
+++ b/src/i18n/locales/es/translations.json
@@ -601,7 +601,9 @@
     "config_error_missing_canonical": "Al algoritmo personalizado \"{{name}}\" le falta una URL canónica válida.",
     "target_repo_required_on_load": "A este proyecto le falta un repositorio de destino. Configure el repositorio de destino para ver los candidatos guardados.",
     "create_similar": "Crear similar",
-    "create_similar_name": "Copia de {{name}}"
+    "create_similar_name": "Copia de {{name}}",
+    "use_lexical_variants": "Usar variantes léxicas",
+    "use_lexical_variants_description": "Amplíe la búsqueda $match para incluir variantes ortográficas en inglés (p. ej. color/colour, leukemia/leukaemia) al comparar nombres de conceptos."
   },
   "app": {
     "web_version": "Versión Web",
diff --git a/src/i18n/locales/zh/translations.json b/src/i18n/locales/zh/translations.json
index 698a800..3273dbb 100644
--- a/src/i18n/locales/zh/translations.json
+++ b/src/i18n/locales/zh/translations.json
@@ -626,7 +626,9 @@
     "config_error_missing_canonical": "自定义算法“{{name}}”缺少有效的规范 URL。",
     "target_repo_required_on_load": "此项目缺少目标仓库。请先配置目标仓库，才能查看已保存的候选项。",
     "create_similar": "创建类似项目",
-    "create_similar_name": "{{name}} 的副本"
+    "create_similar_name": "{{name}} 的副本",
+    "use_lexical_variants": "使用词汇变体",
+    "use_lexical_variants_description": "扩展 $match 搜索范围，以在匹配概念名称时包含英语拼写变体（例如 color/colour、leukemia/leukaemia）。"
   },
   "app": {
     "web_version": "Web 版本",