Solitary eccrine syringofibroadenoma with prominent plasma cell infiltration

Eccrine syringofibroadenoma (ESFA) is a rare, benign, adnexal neoplasm thought to be eccrine ductal differentiation displaying variable clinical findings and characteristic histological features. It usually occurs as a solitary nodule on the extremities of an elderly person. Histological findings typically show a proliferation of anastomosing strands, cords, and columns of monomorphous epithelial cells that harbor eccrine duct formations embedded in a fibrovascular stroma. Acrosyringial nevus, though usually regarded as an identical lesion, is sometimes regarded as a different entity showing prominent plasma cell infiltration. We report two cases of solitary ESFA with prominent plasma cell infiltration. Clinicopathological features of both cases suggest that acrosyringeal nevus and ESFA may be of the same disease entity. Prominent plasma cell infiltration may be just one of the common histological features of ESFA.