Papillary eccrine adenoma--a case of cutaneous sweat gland tumor with secretory and ductular differentiation.

We report a case of the papillary tubular adenoma (PTA) with histological features of differentiation toward secretory and ductal portions of the eccrine gland (papillary eccrine adenoma). The papillary eccrine adenoma (PEA) is a rare benign adnexal neoplasm of the skin characterised by confined growth; however, in some cases it may present a locally aggressive behaviour. This tumor has a unique histopathological appearance, but sometimes the differential diagnosis with other malignant adnexal neoplasms may be difficult and become a source of excessive surgical procedures. We emphasized the need of the assessment of the whole arrangement of the tumor (symmetry, perpendicularity of its long axis to the epidermis, its own fibrous stroma well separated from the surrounding dermis), which prevents the diagnostic pitfalls with adnexal cutaneous carcinomas.