Malignant Peripheral Nerve Sheath Tumor Not Associated with Neurofibromatosis / 대한피부과학회지

ABSTRACT

Malignant peripheral nerve sheath tumor (MPNST) is a rare entity of all soft tissue sarcomas. It has four different types of glandular, melanocytic, rhabdomyoblastic, and epithelioid. Epithelioid MPNST is composed of predominantly epithelioid cells. In contrast, typical MPNST is consisted of spindle cells, which is arranged in a fascicular or whirling pattern. A 33-old man showed two skin-color to reddish brown protruding nodules on the left thigh. Microscopically, one nodule was made up of epithelioid cell, primarily. In addition, the other nodule was composed of epithelioid cells and spindle cells, which also showed Antoni A and B. Immunohistochemical study showed the cells being positive for S-100 protein (weak and focal) and neuron-specific enolase, and negative for HMB-45, smooth muscle actin. Herein, we report a case of two different forms of malignant nerve sheath tumor on the left thigh, which was not associated with neurofibromatosis-1.