| Outbound Relationships | Type | Target | Active | Characteristic | Refinability | Group | Values | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Is a | Letterer-Siwe disease | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Is a | Langerhans cell histiocytosis, disseminated | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Finding site | Lymphoid system structure | false | Inferred relationship | Existential restriction modifier | 2 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Associated morphology | Langerhans cell histiocytosis, disseminated | false | Inferred relationship | Existential restriction modifier | 1 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Associated morphology | Langerhans cell histiocytosis, no International Classification of Diseases for Oncology subtype | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Pathological process | Malignant neoplastic process | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Finding site | Leukocyte | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Course | Persistent embryonic otic artery | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Course | Persistent embryonic hypoglossal artery | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Course | Worth disease | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Course | Boomerang dysplasia | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Finding site | Dendritic cell system structure | false | Inferred relationship | Existential restriction modifier | 1 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Associated morphology | White blood cell abnormality | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Finding site | Hematopoietic system structure | false | Inferred relationship | Existential restriction modifier | 2 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Associated morphology | Malignant neoplasm of primary, secondary, or uncertain origin | false | Inferred relationship | Existential restriction modifier | 2 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Is a | Neoplasm of lymph node | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Is a | Malignant tumor of head and/or neck | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Finding site | Structure of lymph node of head and neck | false | Inferred relationship | Existential restriction modifier | 1 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Associated morphology | Langerhans cell histiocytosis - category | false | Inferred relationship | Existential restriction modifier |  |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Associated morphology | Langerhans cell histiocytosis, disseminated | false | Inferred relationship | Existential restriction modifier | 1 |  | 
| Letterer-Siwe disease of lymph nodes of head, face AND/OR neck | Finding site | Structure of lymph node of head and neck | false | Inferred relationship | Existential restriction modifier | 1 |  |