Wide local excision with tumour-free margins and a sentinel node biopsy was performed.
The final histology showed a high-grade spindle cell tumour, with marked nuclear atypia and 10 mitotic figures per 10 hpf. The value of Ki-67 labelling index was 35 %.
The sentinel node was negative for metastases.
The neoplastic cells were negative for desmin, CD34, CKAE1/AE3, CK34bE12, calponin and positive for AML and vimentin.