60 y.o A male who with baseball sized lesion on back with central ulceration.
-left upper back with 6x5mm erythematous to violaceous mass with central ulceration and surrodning epidermal collarette

-Vimentin: Tumor positive
-Smooth Muscle Actin: Tumor positive
-S100: Tumor negative
-CD34: Tumor negative
-CD68: Tumor negative
-Pancytokeratin: Tumor negative

Consistent with leiomyosarcoma.
Cutaneous leiomyosarcoma sometimes reveals local recurrences, but it has negligible potential for distant metastases (Kaddu et al 1997)
http://www.ncbi.nlm.nih.gov/pubmed/9298873