ABSTRACT
Microcystic adenxal carcinoma is an unusual, locally aggressive neoplasm that has recently been recongized as a clincopathologic entity. Its histologic appearance includes both pilar and eccrine differentiation. Microscopically, the tumor consisted of small cysts and gland-like structures in superficial portion. In other area, basaloid cell nests and abortive hair follicles in the sclerotic stroma were seen. The cysts were filled with secretory eosinophilic material, which was positively stained with Periodic acid-Schiff and carcinoembryonic antigen. Immuno-peroxidase staining for carcinoembryonic antigen supported the dual differnetiation of this neoplasm. Despite the benign histologic appearance, there was deep and extensive infiltration of the subcutaneous tissue.