Desmoplastic nested spindle cell tumor of the liver in an adult

Desmoplastic spindle cell tumor of the liver is a recently described and extremely unusual neoplasm that affects children and young adults. We report 1 case in a 33-year-old man. The patient had abdominal pain and dyspepsia. Abdominal examination showed that the liver was enlarged and palpable until umbilical region. Laboratory studies demonstrated positive serologic markers to hepatitis B virus. All other analytical studies were irrelevant. Computed tomography revealed a large tumor mass in left hepatic lobe showing heterogeneous densities, with hyperdense peripheral areas, as multiple nodular calcifications of less than 1 cm. In the central part of the mass, a big hypodense area was observed. There was no evidence of extrahepatic disease. Grossly, the tumor was well circumscribed with multiple nodular calcifications. The tumor was characterized by the presence of cohesive nests of bland spindle cells arranged in short fascicles and surrounded by desmoplastic stroma, intermixed with epithelioid cells. Mitotic activity was very low. Extensive osteoid formation was seen inside the cell nests. The tumor cells showed cytoplasmic reactivity for vimentin and pan-cytokeratin. The cells of desmoplastic stroma were immunoreactive for actin. The biologic behavior is still uncertain with only 5 published cases, but current information suggests that they are low-grade tumors with an indolent course. The clinical and morphologic features of this tumor are very similar to those of tumors previously reported as "nested stromal-epithelial tumor of liver" and "ossifying stromal-epithelial tumor of liver." We describe the histologic, immunohistochemical, and molecular genetic features of a case of desmoplastic spindle cell tumor of the liver and review the literature.