Malignant peripheral nerve sheath tumor of the pleura with epithelial and rhabdomyoblastic differentiation -: Report of a case clinically simulating mesothelioma

A primary malignant peripheral nerve sheath tumor (MPNST) of the pleura that clinically mimicked a malignant mesothelioma in a 57-year-old man is described. Histologically, the tumor had features similar to those described in cases of the so-called epithelioid MPNST. A unique finding in this case was the demonstration of keratin expression in the epithelioid component of the tumor, as well as the presence of rhabdomyoblasts. This is the first example of an MPNST with heterologous elements arising in the pleura. Immunohistochemical and ultrastructural studies were important in differentiating this tumor from other malignancies with sarcomatoid and epithelioid features involving the pleura.