| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Entire retroperitoneal region, excluding major organs | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of periureteral tissue | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of periadrenal tissue | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Perirenal tissue structure | Is a | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of peripancreatic tissue | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of retropancreatic tissue | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Perinephric hematoma | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 3 | 
| Overlapping malignant neoplasm of retroperitoneum and peritoneum | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal haematoma | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Drug-induced retroperitoneal fibrosis | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Malignant retroperitoneal fibrosis | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Chronic peri-aortitis | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Iliopsoas abscess | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Metastasis to retroperitoneum of unknown primary | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal sarcoma | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Neoplasm of retroperitoneum | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Retroperitoneal lymphadenopathy | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Disorder of retroperitoneal region, excluding major organs (disorder) | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retrocecal abscess | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Retroperitoneal xanthogranuloma | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal abscess | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Incision and drainage of retroperitoneal abscess | Procedure site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Retroperitoneal fibrosis | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal mass | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Benign neoplasm of retroperitoneum (disorder) | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Primary malignant neoplasm of periadrenal tissue | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Primary malignant neoplasm of retroperitoneum (disorder) | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Secondary malignant neoplasm of retroperitoneum (disorder) | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Neoplasm of uncertain behavior of retroperitoneum (disorder) | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal edema | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal hemorrhage | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Malignant retroperitoneal tumour | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Malignant neoplasm of perinephric tissue | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Malignant neoplasm of retrocaecal tissue | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Benign neoplasm of perinephric tissue | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Benign neoplasm of retrocecal tissue | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| benign retroperitoneal tumör i bindväv och mjukdelar | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Neoplasm of uncertain behavior of retroperitoneum and peritoneum | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Neoplasm of uncertain behavior of retroperitoneum | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Abscess iliopsoas non-tuberculous | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Malignant neoplasm of retroperitoneum NOS | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Neoplasm of uncertain behavior of retroperitoneum or peritoneum NOS | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal fat necrosis | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Retroperitoneal cyst | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Pneumoretroperitoneum | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Injury of retroperitoneum with open wound into abdominal cavity | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 3 | 
| Injury of retroperitoneum without open wound into abdominal cavity | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Retroperitoneum injury without mention of open wound into cavity | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Retroperitoneal infection (disorder) | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of iliopsoas muscle | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Retroperitoneal hemorrhage | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal edema | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Drug-induced retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Neoplasm of uncertain behavior of retroperitoneum (disorder) | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Malignant retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Idiopathic retroperitoneal fibrosis | Finding site | False | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Idiopathic retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Structure of perirenal region | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of lymphatic vessel of kidney (body structure) | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Periadrenal region | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Postprocedural retroperitoneal abscess (disorder) | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 3 | 
| Retroperitoneal infection (disorder) | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Repair of retroperitoneal tissue | Procedure site - Direct (attribute) | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal tissue operations | Procedure site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Vascular structure of kidney | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of retroperitoneal lymph node | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Structure of lumbar lymph node | Is a | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some |  | 
| Pneumoretroperitoneum | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 1 | 
| Retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Malignant retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Drug-induced retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 | 
| Idiopathic retroperitoneal fibrosis | Finding site | True | Structure of retroperitoneal region, excluding major organs | Inferred relationship | Some | 2 |