Magnetic resonance imaging of disorders with white matter changes in children and adolescents: a pictorial essay.

White matter changes are seen in a spectrum of disorders in children and adolescents. Understanding their distribution and appearance helps to reach diagnoses in daily radiologic practice. This pictorial essay will outline the magnetic resonance imaging (MRI) appearances of diseases with white matter changes including demyelinating diseases, dysmyelinating disorders/leukodystrophies, infections, autoimmune diseases, vascular causes, mitochondrial disorders and neurocutaneous syndromes, along with a brief overview of clinical aspects of the diseases such as typical age of presentation, etiology, symptoms and signs and treatment options.

Case 237: Renal Cell Carcinoma with Osseous Metaplasia.

History A 47-year-old man presented with palpitations and decreased exercise tolerance. A peripheral blood smear revealed anemia, thrombocytopenia, and blast cells, and a diagnosis of acute myeloid leukemia was made. Immunohistochemistry revealed positivity for cluster of differentiation (or CD) markers, which have been reported to be associated with an increased risk of extramedullary leukemic involvement.

Angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in a Chinese paediatric population.

Objective: To identify specific angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in Chinese paediatric patients.

Design: Retrospective cross-sectional observational study.

Setting: Four locoregional tertiary neurosurgical centres in Hong Kong: Queen Elizabeth Hospital, Tuen Mun Hospital, Kwong Wah Hospital, and Pamela Youde Nethersole Eastern Hospital.

Isolated spinal artery aneurysm: a rare culprit of subarachnoid haemorrhage.

Isolated spinal artery aneurysm is a rare lesion which could be accountable for spontaneous spinal subarachnoid haemorrhage. We describe the case of a 74-year-old man presenting with sudden onset of chest pain radiating to the neck and back, with subsequent headache and confusion. Initial computed tomography aortogram revealed incidental finding of subtle acute spinal subarachnoid haemorrhage.

Bedside ultrasound-guided percutaneous cystostomy in an infant in the neonatal intensive care unit.

We describe a case of an infant born at 39 weeks of gestation who was in the neonatal intensive care unit for postoperative management of congenital heart disease and underwent bedside ultrasound-guided percutaneous cystostomy to treat an iatrogenic urethral injury. The procedure was uneventful, successful, and no complications were noted. This case demonstrates that this procedure is safe and minimally invasive.

Magnetic resonance imaging features of vascular leiomyoma of the ankle.

Vascular leiomyoma is a benign soft tissue tumour with a predilection for middle-aged women. It is most often seen in the extremities, particularly in the lower leg. The typical lesion is a small, slow-growing subcutaneous nodule.

Limitation of radiological T3 subclassification of rectal cancer due to paucity of mesorectal fat in Chinese patients.

Objectives: To describe the thickness of mesorectal fat in local Chinese population and its impact on rectal cancer staging.

Design: Case series.

Setting: Two local regional hospitals in Hong Kong.

Scrotal wall metastasis as the first manifestation of primary gastric adenocarcinoma.

Metastases to the scrotal wall are very rare, and being the initial manifestation of occult primary tumours is even rarer. We report on a patient presenting with painless scrotal swelling, attributed to a solid extra-testicular mass found on ultrasonography. Subsequent investigations and surgical exploration revealed it to be a scrotal wall metastasis from an occult gastric primary.