| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| [M] Small cell osteosarcoma | Is a | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier |  | 
| Osteosarcoma of bone | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Osteosarcoma of bone | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of pelvis | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 2 | 
| Primary osteosarcoma of pelvis | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 2 | 
| Primary osteosarcoma of pelvis | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 3 | 
| Primary osteosarcoma of bone of jaw | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of articular cartilage of jaw | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 2 | 
| Primary osteosarcoma of articular cartilage of jaw | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 3 | 
| Primary osteosarcoma of bone of limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of articular cartilage of limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 2 | 
| Primary osteosarcoma of articular cartilage of limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 3 | 
| Primary osteosarcoma of articular cartilage of pelvis | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 2 | 
| Primary osteosarcoma of articular cartilage of pelvis | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 3 | 
| Osteosarcoma, limb anomalies, erythroid macrocytosis syndrome | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 3 | 
| Osteosarcoma, limb anomalies, erythroid macrocytosis syndrome | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 4 | 
| Primary osteosarcoma | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of articular cartilage of pelvis | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of articular cartilage of lower limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Osteosarcoma of bone of head | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of articular cartilage of jaw | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of right lower limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of right foot | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of left foot | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of left lower limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of vertebral column | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of mandible | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of left hand | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of right hand | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of left upper limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of bone of right upper limb | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of left scapula | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| Primary osteosarcoma of right scapula | Associated morphology | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier | 1 | 
| [M] Small cell osteosarcoma | Is a | False | Osteosarcoma, no International Classification of Diseases for Oncology subtype | Inferred relationship | Existential restriction modifier |  |