Large surgically resected leiomyosarcoma of the liver: a case report

Primary hepatic leiomyosarcoma (PHL) is an extremely rare type of tumor. We herein report a case of a large surgically resected leiomyosarcoma of the liver.

A 69-year-old man with a feeling of epigastric compression was referred for examination of an abdominal mass. He had no history of liver disease or alcohol abuse. Liver function tests indicated Child-Pugh class A. Tumor markers were negative. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a relatively well-contrasted 12 × 11 × 8 cm tumor with well-defined boundary replacing the lateral segment of the liver alongside multiple intrahepatic metastases. Several nodules up to 12 mm were found in both lungs, suggestive of metastasis. SUVmax of the liver mass and lung tumor in positron emission tomography were 10.4 and 1.5, respectively. Hepatocellular carcinoma was primarily suspected. Lateral segmentectomy of the liver was performed to confirm diagnosis and prevent tumor rupture. Macroscopically, the lateral segment of the liver had been replaced by a lobular or multinodular tumor with a maximum diameter of 15 cm. In pathological findings, the tumor consisted of bundle-like proliferation of complicated banding spindle-like cells with clear cytoplasm, accompanied by storiform pattern and compressed blood vessels. Nuclear fission images were observed in 8/10 HPF. Partial necrosis was present, with associated venous invasion and intrahepatic metastasis. Immunohistochemical staining for tumor cells revealed desmin, α-smooth muscle actin (αSMA), and h-caldesmon were all positive, informing a final diagnosis of PHL. The postoperative course was uneventful, and he was discharged on the 12th postoperative day.

PHL is a rare malignant disease with relatively poor prognosis. To confirm a diagnosis of PHL, immunohistochemical analysis as well as histopathological findings is important. The preferred treatment is surgical resection, sometimes in combination with adjuvant chemotherapy and radiotherapy. Further studies are needed to elucidate and better understand this uncommon clinical entity.