Cylindroma and eccrine spiradenoma coexistent in the same lesion

Two patients complained of having a tender nodule. One patient had the nodule on the scalp and the other on the face. Each nodule contained a cylindroma and an adjacent eccrine spiradenoma. While eccrine spiradenoma is of eccrine derivation, the origin of cylindroma is controversial because of variable histochemical and enzyme histochemical findings. The presence of cylindroma and eccrine spiradenoma in one clinical nodule contributes circumstantial evidence for the similar derivation of both tumors.