Abstract: Objective:To summarize the computed tomography (CT) characteristics of primary hepatic angiosarcoma (PHA).
Methods:The retrospective cross-sectional study was conducted. The clinicopathological data of 9 PHA patients who were admitted to the Wenzhou Chinese Medicine Hospital (3 patients), Second Affiliated Hospital of Wenzhou Medical College (3 patients) and Wenzhou People′s Hospital (3 patients) between January 2006 and June 2017 were collected. All 9 patients were fasting 8 hours before CT examination, and received screen scans without abdominal pressure. Scanning area was from dome of diaphragm to lower pole of the kidneys. Two associate senior doctors made images analysis. After preoperative examinations, patients selected whether or not to undergo treatment, resection, liver transplantation or chemotherapy + targeted therapy of monoclonal antibodies. Observation indicators: (1) plain scan appearances of CT; (2) enhanced scan appearances of CT; (3) results of pathological examinations; (4) follow-up and survival situations. Follow-up using outpatient, inpatient and imaging examinations was performed to detect tumor recurrence and stable condition up to December 2017.
Results: (1) Plain scan appearances of CT: 9 patients showed solitary tumor, and tumors were respectively located in the left lobe (3 cases) and right lobe (6 cases) of the liver, including 5 with round tumors, 3 with oval tumors and 1 with patchy tumor. The maximum diameter of tumor was 5.8-16.0 cm, with an average of 10.8 cm, including maximum diameter > 6.0 cm in 8 patients. Tumors of 9 patients showed low-density shadow, and CT value was 32-46 HU, with an average of 41 HU, including homogeneous density in 3 patients and heterogeneous density in 6 patients; clear tumor boundary in 6 patients and unclear tumor boundary in 3 patients; tumor necrosis and cystolization in 4 patients, slightly strip-shaped high-density shadow in the center of tumor in 4 patients, and small patch-shaped intratumoral calcification in 1 patient. (2) Enhanced scan appearances of CT: ① Arterial phase: tumors of 9 patients showed mild and moderate heterogeneous enhancements, with CT value of 63-76 HU and an average of 68 HU, including small patch-shaped or nodular enhancement in 3 patients and punctate or flocculent enhancement in the center of tumor in 6 patients. Tumors of 4 patients showed moderate enhancements, and tumor density was higher than that of normal liver parenchyma. Tumors of 5 patients showed mild enhancements, and tumor density was equal to or slightly less than that of normal liver parenchyma. ② Portal vein phase: tumors of 9 patients showed mild and moderate, continuous and progressive enhancements, with a heterogeneous density, CT value of 56-71 HU and an average of 63 HU, including extended enhancement region in 3 patients, with a fusion and filling trend; small patch-shaped or nodular and lattice network-shaped enhancements of center and periphery of tumor in 6 patients, showing center filling and enhancement features of hepatic angiosarcoma. Tumors of 2 patients showed moderate enhancements, and tumor density was higher than that of normal liver parenchyma; tumors of 7 patients showed mild enhancements and tumor density was equal to or slightly less than that of normal liver parenchyma. ③ Delayed phase: tumor enhancements of 9 patients slowly seceded, with CT value of 50-60 HU and an average of 53 HU, including density decreasing of periphery of tumor in 3 patients; partial fusion and center filling of enhancements in 6 patients, without enhancement in necrotic area. Tumor density was slightly higher than that of normal liver parenchyma in 2 patients, equal to that of normal liver parenchyma in 1 patient, and slightly less than that of normal liver parenchyma in 6 patients. (3) Results of pathological examinations: ① Pathological examinations: cut surface of tumors showed grayish yellow and drab gray, and parts of surface were fish flesh shape, with internal bleeding and necrosis. Tumors were found in diffuse hyperplasia under microscopy, tumor tissues were made up of irregular and mutual matching lacuna vasorum, with infiltrating growths along hepatic sinus gap; hepatic angiosarcoma cells were spindle, round or irregular; there were slightly eosinophilia cytoplasm and deep chromatin of the nucleus, long-shaped or irregular nucleus, and different sizes of nucleolus. ② Immunohistochemical staining: CD31 and CD34 were strongly positive, vimentin and Nestine were positive, and CK19, actin and creatine kinase were negative. (4) Follow-up and survival situations: of 9 patients, 3 without treatment respectively died at 3, 6 and 7 months; 2 had recurrence at 4 and 5 months after tumor resection, with angiosarcoma invading right renal capsule, diaphragm and right pleural hemorrhage induced to haemothorax, and survived respectively for 13 and 15 months; 2 respectively died of systemic metastasis at 4 and 8 months after liver transplantation; 2 underwent chemotherapy + targeted therapy of monoclonal antibodies, and survived for 12 months.
Conclusions:CT appearances of PHA have certain characteristics. The plain scans of CT show heterogeneous low-density shadow, and enhanced scans of CT show small patch, punctate or nodular-shaped, continuous and progressive enhancements, with a clear boundary between tumor and liver parenchyma.