Teaching Case

A 64-year-old man with a history of hepatitis B virus-related cirrhosis was referred to our Emergency Department due to vasovagal syncope, hypotension (BP: 107/57) and intense right flank pain for 24 hours. Laboratory examination showed Hb: 12g/dl (Normal range: 13-17) and acute renal failure (Cr: 2.1 mg/dl).

Ultrasound and multiphase MSCT study of the abdomen showed moderate and hyperdense ascites with a sentinel clot in the left anterior perihepatic space without active bleeding. The liver had morphological changes of chronic liver disease. A 5 cm in size, subcapsular and heterogeneous solid mass between segments II-III was identified. MSCT displayed a hypervascular dynamic behaviour in the arterial and portal phase, a mosaic pattern and a contrast wash-out at the equilibrium phase, in which a peripheral capsule was suspected.
The radiological diagnosis was haemoperitoneum due to spontaneous rupture of hepatocellular carcinoma. Therefore, transarterial catheter embolization with microspheres was performed.

Background

Hepatocellular carcinoma (HCC) is the most frequent malignant liver neoplasia. Spontaneous rupture of HCC is a rare and potentially fatal complication with a reported incidence of 3 to 15%, especially in cirrhotic patients with associated coagulopathy. The rupture may be intratumoural or into the peritoneal cavity. The smaller anatomical extent of the left hepatic lobe favours an exophytical growth pattern and subsequent rupture in HCC [1, 2, 3].
The mechanism of rupture of HCC is poorly understood. It is believed that subcapsular tumours may destroy the liver capsule by high intramural pressure or direct invasion [1, 3]. Other authors consider the injury of a feeding tumoural artery under high intraabdominal pressure secondary to ascites as the cause of rupture. Another hypothesis is a laceration in the surface of the tumour by minimal trauma [3]. Venous congestion (secondary to vascular invasion), intratumoural necrosis and the presence of coagulopathy, may lead to intratumour haemorrhage. [4, 5]

Clinical perspective

Patients may experience an acute abdominal pain, abdominal distension, hypotension, and a sudden decrease in haematocrit and haemoglobin. [1]

Imaging perspective

MSCT is the first-line modality of choice. The appropriate CT protocol for this entity is 4-phase dynamic study (precontrast, arterial, portal and equilibrium phase). The role of CT in HCC work-up is the detection, characterization, staging of the tumour and assessment of complications. Helpful findings on CT for the diagnosis of spontaneous rupture of HCC are: peripheral location and protrusion of the tumour, discontinuity of the hepatic surface, active extravasation of iv contrast, haemoperitoneum, subcapsular haematoma and the presence of a sentinel clot. [3, 4, 5]

Outcome

The spontaneous rupture of HCC requires prompt resection or transarterial catheter embolization, so early diagnosis is essential. The success rate for haemostasis after transarterial catheter embolization ranges from 53 to 100% and mortality ranges from 0 to 36.4%, which is lower than that of emergency surgery. [1, 3]
Knowledge of complications of hepatocellular carcinoma and its CT findings are important for the radiologist as it is an entity that may require prompt treatment.