Case Report
Bednar Tumour Occurring after Malignant Melanoma Excision
Table 2
Bednar tumour: differential diagnosis by immunohistochemistry (SCC: squamous cell carcinoma; MM: malignant melanoma; SS: synovial sarcoma).
| ā | Bednar tumour | Pigmented neurofibroma | Leiomyosarcoma | SCC | MM | SS | Solitary fibrous tumour |
| CD34 | + (spindle) | - | - | - | - | - | + |
| Vimentin | + (spindle) | + (diffuse) | + | - | - | + | + |
| S100 | + (pigmented) | + (focal) | - | - | + | -/+ (40%) | - |
| -actin | - | - | + | - | - | - | + |
| Desmin | - | - | + | - | - | - | - |
| Cytokeratin | - | - | - | + | - | + (90%) | - |
| Melan-A | + (pigmented) | - | - | - | +/- | - | - |
| HMB-45 | + (pigmented) | - | - | - | +/- | - | - |
| CD99 | +/- (80%) | - | - | - | - | + | + |
| EMA | - | - | - | + | - | + (50%) | + |
| BCL-2 | + | - | - | - | - | + | + |
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