An Unusual Case of Primary Hepatic Leiomyosarcoma

Abstract

Purpose: Primary hepatic leiomyosarcoma is exceedingly rare and only few cases have been reported in literature. Presentation is usually nonspecific and diagnosis is often delayed until tumors reach a large size. This leads to a dismal prognosis. The tumors are not yet fully understood hence standard of care not yet well defined. Case Presentation: A 51-year-old male patient presented to the hospital with intractable hiccups, poor oral intake and 20 pounds weight loss. He denied abdominal pain, nausea, vomiting or irregular bowel habits. His comorbidities included seizure disorder and hypertension. He had no history of liver disease or alcohol abuse. On physical examination he appeared cachectic. Abdominal examination revealed a hepatomegaly of about 6cm below the right costal margin. Laboratory analysis revealed alanine aminotransferase 81 IU/L (0-34 IU/L), aspartate aminotransferase 56 IU/L (0-40 IU/L) and alkaline phosphatase 160 IU/L (28 -94 IU/L), serum albumin 2.8 g/dl (3.4 -5 g/dl). Serum bilirubin prothrombin time, white blood cells, platelets and α-fetoprotein were normal. Antibody to hepatitis C and hepatitis B surface antigen were negative. Abdominal computed tomography showed a hypodense rim enhancing 3.5 cm by 2.5 cm lesion with a necrotic center within segment VI of the liver. A CT guided biopsy of the lesion revealed a tumor comprised of spindle cells arranged in interlacing pattern. There was minimal nuclear pleomorphism, tumor necrosis and no increase in mitotic activity. Immunomarker stains were positive for smooth muscle actin but negative for desmin, CD117 and CD34. These pathological features were consistent with a diagnosis of spindle cell neoplasm, low grade leiomyosarcoma involving the liver. Discussion: Hepatic tumor of mesenchymal origin is rare, accounting for only 1.2% of all primary hepatic tumors. The most common type of primary malignant mesenchymal tumor is angiosarcoma (36%) followed by leiomyosarcoma, fibrosarcoma and unspecified sarcoma. Most of hepatic leimyosacoma are metastatic from other sites of leiomyosarcoma including gastrointestinal tract, uterus, retroperitoneum and lung. Liver function tests are usually variable while carcinoembryonic antigen and α-fetoprotein are normal. Cut surface of the liver is often pinkish-white with yellow areas of necrosis or dark red hemorrhagic foci. Mean survival of untreated hepatic leiomyosarcoma is dismal (about 10 months). Surgical excision appears to prolong survival however chemotherapy is the alternative therapy for inoperable patients. In conclusion we present a rare case of primary hepatic leiomyosarcoma. Prognosis is poor and clinical diagnosis is challenging in cases of small tumors.