Table 2: Bednar tumour: differential diagnosis by immunohistochemistry (SCC: squamous cell carcinoma; MM: malignant melanoma; SS: synovial sarcoma).

Bednar tumourPigmented neurofibromaLeiomyosarcomaSCCMMSSSolitary 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+----++