Cellular-type neurothekeoma over the chest wall of a woman

A 33-year-old woman with no underlying systemic disease visited our hospital with a tender, hyperpigmented skin tumor over the right lateral chest wall for 6 months. Initially, the lesion was a small hemorrhagic cutaneous papule. Perifocal hyperpigmentation developed progressively and the lesion gradually enlarged to 2 cm at its greatest diameter. On physical examination, a painful illdefined mass-like lesion was palpated over the right lateral chest wall. It was a 1 2 cm2 ovoid hyperpigmented skin patch with a 0.3-cm papule in the center (Fig. 1A). A simple excision was performed. After the operation, the patient recovered uneventfully and has had no local recurrence. The histological examination revealed lobulated solid nests and strands of large epithelioid cells with vesicular nuclei, minimal nuclear atypia, pale cytoplasm, and rare mitoses, with infiltration into the dermis (Fig. 1B). Immunohistochemically, the tumor cells were positive for vimentin and CD57 and negative for CD34, epithelial membrane antigen (EMA), human melanoma black 45, estrogen receptor, S-100, and cytokeratin. These features were consistent with a cellular variant of neurothekeoma. Neurothekeoma is a type of benign nerve sheath neoplasm and presumably arises from small cutaneous nerves [1,2]. Neurothekeomas have been classified as myxoid, cellular, or mixed type. However, myxoid-type neurothekeomas have a relatively high local recurrence rate when managed by simple local excision and appear to be unrelated to cellular and mixed-type neurothekeomas.