[Immunohistochemical detection of calmodulin. A contribution to the histogenetic classification of eccrine poroma and clear cell acanthoma].

In previous immunohistochemical studies calmodulin (CaM) was detected in the sweat duct. In further investigations we searched for CaM-reactivity in eccrine poromas and clear cell acanthomas. CaM was only detectable in whorl-like areas, so confirming the concept of a ductal origin of this tumor. CaM-reactivity was failing in both, intraepidermal and malignant eccrine poroma. Acanthomas with clear cell pattern failed to give uniform results, suggesting a heterogenous origin of clear cells in the tumours investigated.