Malignant schwannoma of the liver.

Malignant schwannoma is the most common soft tissue sarcoma in adults, but primary schwannoma of the liver is extremely rare. We report an autopsy case of malignant schwannoma of the liver in a 63-year-old man. The tumor involved almost the entire right lobe of the liver. Microscopically, it was composed of moderately pleomorphic spindle cells with hyperchromatic nuclei with mitotic figures. The spindle cells were stained positively with antibodies to both S-100 protein and vimentin. Necrosis was found in the primary tumor. Only four other cases of malignant schwannoma of the liver were found in a review of the literature. Pertinent features of these tumors are discussed.