The light and electron microscopy study of a so-called low grade or semimalignant Schwannoma in the liver of a 74 year-old white man without von Recklinghausen's disease is reported. The diagnosis relied on the histological findings of numerous moderately pleomorphic fusiform cells with hyperchromatic nuclei, areas of necrosis, the local infiltrative pattern with absence of metastasis at autopsy, the huge size (21 X 12 X 8 cm) and the clinical data of rapid growth pattern associated with marked body weight loss. The proper identification in surgical specimens of this kind of neoplasias would lead to more appropriate therapeutic approach.