diff --git a/src/ontology/uberon-edit.obo b/src/ontology/uberon-edit.obo
index 281bbce91..04de98941 100644
--- a/src/ontology/uberon-edit.obo
+++ b/src/ontology/uberon-edit.obo
@@ -225635,6 +225635,19 @@ is_a: UBERON:0006914 ! squamous epithelium
 relationship: has_part CL:4030023 ! respiratory tract hillock cell
 relationship: part_of UBERON:0007196 ! tracheobronchial tree
 
+[Term]
+id: UBERON:9900001
+name: sinus of lymph node
+def: "A sinus located in a lymph node. Lymph nodes have subcapsular, cortical (trabecular) and medullary sinuses." [Wikipedia:Lymph_node]
+synonym: "lymphatic sinus" EXACT []
+synonym: "lymph node sinus" EXACT []
+intersection_of: UBERON:0000464 ! anatomical space
+intersection_of: part_of UBERON:0000029 ! lymph node
+relationship: dc-contributor https://orcid.org/0000-0001-5858-4393 ! John Fostel
+property_value: dcterms-date "2025-11-03T00:00:00Z" xsd:dateTime
+created_by: dragon-ai-agent
+property_value: term_tracker_item "https://github.com/obophenotype/uberon/issues/3586" xsd:anyURI
+
 [Typedef]
 id: aboral_to
 name: aboral to