[Cellular neurothekeoma, a rare cutaneous tumor. Anatomo-clinical and immunohistochemical study of 2 cases].

Cellular neurothekeoma is an unusual cutaneous tumor described in 1986. We report two new cases in 14-year-old girls. Both tumors measured less than one centimeter and were located on the forearm and the shoulder. They had a plexiform architecture and were developed in the dermis and the dermo-hypodermic junction. Spindle and epithelioid tumor cells were immunoreactive for vimentin, NKI-C3, NSE, CD68 and smooth muscle actin. There was no recurrence 2 and 7 months after the operation. Cellular neurothekeoma is a benign tumor. Its histogenesis is still unknown. Histological and immunohistochemical features, with positivity of the tumor cells for NKI-C3, a non specific melanocytic marker, and negativity for S-100 protein and HMB-45, allow to differentiate cellular neurothekeoma from myxoid neurothekeoma and melanocytic tumors.