Chronic expanding hematoma of the liver: a case report and review of the literature.

Chronic expanding hematoma (CEH) is defined as a hematoma that grows slowly over a month or longer. CEH with a primary hepatic origin is extremely rare. An 85-year-old man presented with general malaise and low-grade fever. His medical history included hypertension and postoperative appendicitis, and he was taking oral aspirin. Computed tomography showed a 7-cm mass in liver S7 with calcification at the margin. On contrast-enhanced magnetic resonance imaging, the inside of the mass showed heterogeneous hyperintensity on T1-weighted images, mainly low intensity on T2-weighted images, and mild hyperintensity in some areas. Under the preoperative diagnosis of suspected CEH, hemorrhagic cyst, or hepatocellular carcinoma, S7 partial liver resection and cholecystectomy were performed. Histopathological findings showed that the mass was continuous with the liver and protruded extrahepatically, and was covered with a hard fibrous capsule. The capsule contained hematomas ranging from obsolete to relatively fresh, with no neoplastic lesions. He was diagnosed with CEH in the liver. This subcapsular hepatic hematoma was pathologically shown to be a CEH. Complete surgical resection was effective in treating this CEH in the liver.