Giant haemorrhagic hepatic cyst with flame-like morphology in a patient with polycystic kidney and liver disease.

INTRODUCTION: Intracystic haemorrhage is a rare complication of hepatic cysts, and is often mistaken for a malignant lesion. CASE REPORT: A 55-year-old female with a history of polycystic kidney and liver disease presented with a six-month history of abdominal distension, abdominal pain, early satiety, shortness of breath and 5 kg of weight loss. Imaging revealed a 20 cm mixed solid-cystic hepatic lesion containing peripheral avascular mobile echogenic material with a flame-like morphology. After experiencing symptomatic relief from ultrasound-guided aspiration, the patient underwent cyst fenestration for more definitive treatment. DISCUSSION: Haemorrhagic hepatic cysts are uncommon and may present on imaging as having lace-like retractile clot, internal layering or shading of separating blood products or avascular mobile flame-like excrescences. The presence of avascular mobile flame-like excrescences appears to be a unique feature of haemorrhagic hepatic cysts. CONCLUSION: While haemorrhagic hepatic cysts are rare and commonly mistaken for biliary cystadenomas or adenocarcinomas, the identification of particular features on high-resolution magnetic resonance imaging and contrast-enhanced ultrasound can lead to the correct diagnosis.

Magnetic resonance imaging features of gemistocytic astrocytoma.

INTRODUCTION: Gemistocytic astrocytoma is the second most common subtype of World Health Organization grade 2 astrocytoma, but has a worse prognosis than other grade 2 lesions. We aim to describe the MR imaging features of histopathologically proven gemistocytic tumours. METHODS: Ethics approval was obtained from both institutions. Patient consent was not required for this retrospective study. We reviewed MR imaging findings of 16 consecutive cases of histopathologically proven gemistocytic astrocytoma and anaplastic astrocytoma with gemistocytic features. RESULTS: Average patient age was 48 years, with a 3:1 male to female ratio. Based on our series, the typical appearance of a gemistocytic astrocytoma is a large, heterogeneous mass most commonly supratentorial and lobar. Regions of cyst formation, partial signal suppression on FLAIR images and contrast enhancement are all common features. Additionally, contrary to previous literature that describes gemistocytic astrocytoma as a purely supratentorial lesion, we present two cases of gemistocytic astrocytoma involving the brainstem. CONCLUSIONS: The possibility of gemistocytic astrocytoma should be considered in patients presenting with large heterogeneous tumours that have regions of cyst formation, partial FLAIR suppression and contrast enhancement. This may be especially useful in reconciling a lesion with high-grade MR imaging features with low-grade histopathology. An infratentorial location does not preclude the diagnosis of gemistocytic astrocytoma.