ABSTRACT
Eccrine spiradenoma is a benign tumor that is differentiated into the direction of an eccrine gland. It is usually presents as a solitary, slowly-growing, intradermal or deeply subcutaneous nodule on the head and trunk. We report on a case of 32-year-old woman with a solitary, solid mass on the left leg that she'd had for 6 months. The mass was a 2.5x2x0.5 cm sized, round shaped, well demarcated solitary skin-colored nodule. The mass in our case was a relatively large and painful eccrine spiradenoma, and the mass showed cystic formation. The cyst was surrounded by cords of tumor cells. Hyaline materials were seen focally. There were two types of cells. Large pale nuclei existed adjacent to the cyst. Small dark nuclei existed at the periphery. To clarify the histogenesis of this tumor, immunohistochemical staining using various antibodies was also performed. We herein report on an unusual case of a large cystic eccrine spiradenoma.