Teaching Case

Several hours before admission to the hospital the patient felt sudden and severe diffuse abdominal pain radiating posteriorly and was vomiting.

Several hours before admission to the hospital the patient felt sudden and severe diffuse abdominal pain radiating posteriorly and was vomiting. Upon arrival, examination yielded low blood pressure, tachycardia, and marked decrease of hematocrit (0.22). Precontrast CT scan revealed a massive hematoma occupying most of the right liver and hemoperitoneum (fig. 1). Contrast -enhanced spiral CT scan during arterial phase showed a small hypervascular mass in the segment I, suggesting a hypervascular tumor (hepatocellular adenoma or hepatocellular carcinoma) as bleeding source (fig 2). CT scan during portal venous phase showed pooling of contrast medium suggesting active bleeding (fig 3). At laparotomy, a massive intraperitoneal bleeding arising from a large tumor of the right liver lobe was found. Pathological examination revealed a liver cell adenoma.

Hepatocellular adenoma (HA) is an uncommon, usually well-defined, encapsulated benign liver tumor composed of sheets of hepatocytes without bile ducts or portal areas. Kupffer cells are reduced in number or absent. It may appear spontaneously in both genders but it occurs predominantly in women of younger age with a history of oral contraceptive use. Rare documented cases of HA in male patients are associated with the use of anabolic-androgen steroids. Other conditions associated with a higher incidence of HA are diabetes mellitus and type 1 glycogen storage disease. Multiple adenomas are associated with glycogen storage disease. HA may be found incidentally during an examination for unrelated reasons, but most often they are symptomatic. Clinical symptoms include: acute and chronic pain, palpable mass, and abnormal liver function. Because HA bears a low risk of malignant transformation and is prone to spontaneous bleeding (especially tumors larger then 5 cm) surgical treatment is recommended. There are no specific imaging modalities for HA. During preoperative planning, the main differentiation should be made between HA and other benign hepatic tumors, especially focal nodular hyperplasia (also more encountered in women) and hemangioma (the most common benign hepatic tumor). Both are very rarely a cause of spontaneous bleeding, and malignant transformation does not occur. Differentiation between these tumors and HA is achieved with high sensitivity, specificity and accuracy with labeled red blood cells, cholescintigraphy in combination with ultrasound, and contrast-enhanced dynamic CT. Presence of necrosis and bleeding is suggestive of HA. Spontaneous hepatic bleeding is rare but an emergency and potentially lethal condition. In the absence of trauma or anticoagulant medication in elderly men the main cause of hepatic bleeding is hepatocellular carcinoma. Very rarely a HA may be the cause of spontaneous tumor bleeding.