Posterior reversible encephalopathy syndrome (PRES): features on CT and MR imaging.

Posterior reversible encephalopathy syndrome (PRES) is a rare but severe condition of the central nervous system. It develops in a variety of clinical settings and it has diverse patterns of expression, which can sometimes make diagnosis difficult. Characteristic features are often demonstrated on computed tomography imaging and/or magnetic resonance imaging, meaning that when there is a suspicious clinical picture, this diagnosis should suggest itself. However, clinicians should be aware of some of the less typical features in order to more fully understand this condition, in which early treatment is key to good clinical progress.

[CT imaging features of colitis in neutropenic patients]. / Aspects tomodensitométriques des colites chez les patients neutropéniques.

Colitis in neutropenic patients presents with non-specific clinical findings including abdominal pain, fever, diarrhea and abnormal liver function tests. Four diagnoses are relatively more frequent: neutropenic enterocolitis, pseudomembranous colitis, intestinal GVHD and CMV colitis. Knowledge of their respective imaging features combined with epidemiological data frequently leads to the correct diagnosis. The purpose of this paper is to illustrate the imaging features of colitis in neutropenic patients.

[Liver capsule retraction adjacent to a circumscribed liver lesion: review of 26 cases with histological confirmation]. / Rétraction capsulaire hépatique en regard d'une lésion circonscrite: à propos de 26 patients avec preuve histologique.

PURPOSE: To review the histological features of 26 circumscribed liver lesions associated with liver capsule retraction and discuss the differential diagnosis while evaluating for the presence of fibrous stromal reaction. Materials and methods. Retrospective study performed between January 2005 and June 2008 including 26 patients: 18 males and 6 females, without history of cancer, aged between 42 and 82 years (mean age: 64.5 years), presenting with liver capsule retraction adjacent to a circumscribed liver lesion detected on CT or MRI. A single lesion was present in 17 patients, and multiple lesions were present in 9 patients. All liver lesions were biopsied with semi-quantitative evaluation of fibrous stromal reaction. RESULTS: Twenty-one patients had benign or malignant liver tumors and 5 patients had confluent hepatic fibrosis. Twenty of 21 liver tumors were malignant (95.2%): 3 intra-hepatic cholangiocarcinoma, 17 cases of metastatic disease including colorectal carcinoma (n=8), bronchogenic carcinoma (n=1), pancreatic carcinoma (n=4), esophageal carcinoma (n=1), breast carcinoma (n=1), gallbladder carcinoma (1) and endocrine neoplasm of the pancreas (n=1), and 1 case of liver sclerosing angioma (n=1). There was no case of hepatoma. Excluding the 5 cases of confluent hepatic fibrosis, fibrous stromal reaction was present in 15 of 21 cases. CONCLUSION: The presence of capsular retraction next to a circumscribed liver lesion, while non-specific, is suspicious. In keeping with previous reports, metastases were frequently the cause and intrahepatic cholangiocarcinoma was the most frequent primary tumor. In patients with chronic hepatocellular disease, confluent fibrosis was a frequent etiology. The fibrous component of the underlying malignant lesion along with its subcapsular location appear to be determining factors in the development of capsular retraction.

[Fibrolamellar hepatocellular carcinoma in a patient with chronic viral B hepatitis]. / Carcinome hépatocellulaire fibrolamellaire chez un patient suivi pour hépatite chronique virale B.

In most cases, fibrolamellar hepatocellular carcinoma has specific and distinctive histopathological features that distinguish it from hepatocellular carcinoma. Magnetic resonance imaging can provide characteristic features to obtain a diagnosis of this entity. We report a case of fibrolamellar hepatocellular carcinoma with a radiological-pathological correlation in a 37 year-old man with chronic viral hepatitis B without cirrhosis who underwent right hepatectomy.

[Superficial siderosis of the central nervous system: a case report]. / Sidérose superficielle du système nerveux central: à propos d'un cas.

Superficial siderosis of the central nervous system is secondary to chronic subarachnoid bleeding. However, the underlying etiology is not always detected. Superficial siderosis can be diagnosed at MRI by the presence of a hypointense rim along the brain surface on gradient echo T2W images. The authors report a case of superficial cerebral siderosis where the underlying etiology remained undiagnosed in spite of extensive neuroradiological work up.