PAPILLARY ECCRINE ADENOMA - IMMUNOHISTOCHEMICAL STUDY AND LITERATURE-REVIEW

A case of papillary eccrine adenoma on the right forearm of a 78-year- old Japanese woman is reported. The tumor was 1.3 cm in diameter, occu pying the whole thickness of the dermis. Histologically, the tumor was composed of dilated tubules of various sizes with intraluminal papill ary projections, and was surrounded by a fibrous stroma. An immunohist ochemical study revealed that the proliferating tubules were composed of a single outermost layer of alpha-smooth muscle actin- and keratin 14-positive myoepithelial cells, and keratin 8-positive inner cells. T his antigen expression pattern was comparable to that of the normal ec crine secretory coil, which indicates that the tumor differentiated to ward the secretory coil of an eccrine sweat gland.