Hepatic leiomyosarcomas: CT features with pathologic correlation.

The purpose of this study was to determine the computed tomographic (CT) features of hepatic leiomyosarcoma and to correlate them with pathologic findings. CT examinations of 15 patients with pathologically proven leiomyosarcoma of the liver were retrospectively reviewed. Three patients had primary leiomyosarcoma of the liver and 12 patients had 43 distinct hepatic metastases originating from a primary gastrointestinal (n = 8), uterine (n = 2) or retroperitoneal (n = 2) leiomyosarcoma. In the 11 patients who had partial hepatic resection or surgical biopsy of their tumors, a correlation was made between CT imaging and pathologic findings. Primary leiomyosarcomas showed heterogeneous enhancement; two displayed internal and peripheral enhancement, and one showed peripheral enhancement with a pseudocystic pattern (i.e. enhancing thick wall with internal nonenhancing low attenuation area). Leiomyosarcomas metastatic to the liver were homogeneous, showing no or moderate enhancement (10 of 43 metastases, 23%) or heterogeneous and predominantly peripheral enhancement (33 of 43 metastases, 77%). A pseudocystic pattern was seen in 13 of the 43 metastases (30%). Homogeneous tumors were made of smooth fibrous-like tissue without area of necrosis. Heterogeneous tumors contained varying degrees of necrosis and hemorrhage or gelatinous tissue. We found that primary and secondary hepatic leiomyosarcomas of the liver can exhibit different features. A pseudocystic pattern is uncommon. Furthermore, purely cystic tumors were not seen in our series.