| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Mast cell hyperplasia | Is a | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier |  | 
| Mast cell neoplasm | Is a | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier |  | 
| Urticaria pigmentosa, adult form | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Urticaria pigmentosa, multiple nodules AND/OR plaques | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Non malignant mast cell disease | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Urticaria pigmentosa, infantile form | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Urticaria pigmentosa | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Urticaria pigmentosa, maculopapular type | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Telangiectasia macularis eruptiva perstans | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Mast cell disorder | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Cutaneous mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Diffuse erythrodermic mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Systemic mast cell disease | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Bullous urticaria pigmentosa | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Mastocytoma | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Mast cell leukemia affecting skin | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Familial mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Mastocytoma | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Diffuse erythrodermic mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Familial mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Mast cell leukemia affecting skin | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Cutaneous mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Telangiectasia macularis eruptiva perstans | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Aggressive systemic mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Reactive mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Urticaria pigmentosa, adult form | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Bullous urticaria pigmentosa | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Diffuse erythrodermic mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Solitary cutaneous mastocytoma | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Familial mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Cutaneous mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 4 | 
| Indolent systemic mastocytosis | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Localized extracutaneous mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 2 | 
| Cutaneous mastocytosis, short stature, hearing loss syndrome | Associated morphology | False | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 6 | 
| Urticaria pigmentosa, infantile form | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Telangiectasia macularis eruptiva perstans | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 4 | 
| Urticaria pigmentosa | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 | 
| Mast cell gastritis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Cutaneous mastocytosis, short stature, hearing loss syndrome | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 1 | 
| Bullous diffuse cutaneous mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 4 | 
| Pseudoxanthomatous nodular cutaneous mastocytosis | Associated morphology | True | Mast cell abnormality | Inferred relationship | Existential restriction modifier | 3 |