Eccrine syringofibroadenoma: a case report with analysis of cytokeratin expression

A 56-year-old man presented with a 30-year history of a slowly enlarging lesion on the sole of his right foot. A biopsy showed an anastomosing network of small cuboidal cells with the formation of occasional sweat ductal lumina and a marked fibrovascular stroma. The histological findings were interpreted as consistent with the diagnosis of an eccrine syringofibroadenoma. Using immunohistochemistry all the tumour cells were positively stained by the pan-cytokeratin antibody Lu-5 and an antibody to the cytokeratins 1/5/10/11. In addition the luminal ductal cells expressed cytokeratin 19 and CEA. Tumour cells were negative for cytokeratins 1, 7, 8, 13 and 18 and did not express vimentin and GCDFP-15. The results indicate that the eccrine syringofibroadenoma is differentiated towards the dermal eccrine duct.