Dysplastic gangliocytoma of the cerebellum in a cat.

A 2.5-year-old cat presented with progressive ataxia and lethargy. Magnetic resonance imaging (MRI) showed enlargement of the cerebellum and herniation of cerebellar vermis. Postmortem examination confirmed the MRI findings, and histopathology showed numerous large dysplastic neurons populating and displacing the Purkinje cell layer and extending into the molecular and granular layers of the cerebellum. The lesion was diagnosed as dysplastic gangliocytoma of the cerebellum. In humans, this tumor is often associated with Cowden syndrome, a genetic disorder characterized by multiple hamartomas and an increased risk of developing certain neoplasms, known to be linked to a germline mutation of the phosphatase and tensin homolog (PTEN) gene. Reduction in PTEN nuclear and cytoplasmic immunohistochemical labeling of dysplastic neurons in this case suggested a possible PTEN mutation involved in the tumorigenesis. This report provides a detailed pathology description of the tumor and the use of neuronal and PTEN markers which will help guide pathologists presented with this rare condition in the future.

Bartonella neuroretinitis (cat-scratch disease).

We report a patient with cat-scratch disease presenting with meningitis and neuroretinitis. This condition, caused by Bartonella henselae, has a worldwide distribution and is among the most common infective causes of neuroretinitis. Bartonella neuroretinitis is a rare but under-recognised mimic of optic neuritis; it should be suspected in a patient with an infective prodrome whose fundus shows optic disc oedema and a macular star. A low-positive initial serological test for Bartonella henselae does not exclude cat-scratch disease if there is high clinical suspicion, and repeat testing is recommended to look for titre rise.

Cheiro-oral syndrome.

We describe a 64-year-old man who presented to the emergency department with a two-day history of left perioral and hand numbness. Examination revealed impaired sensation of the left corner of the mouth and ipsilateral fingers. Neuroimaging showed an acute right thalamic lacunar infarct consistent with the diagnosis of cheiro-oral syndrome. In this report, we discuss the importance of recognising this syndrome and instituting appropriate management to prevent further cerebrovascular events.

Pneumocystis jiroveci prophylaxis in patients undergoing Bendamustine treatment: the need for a standardized protocol.

The decision for PJP prophylaxis depends on a physician's evaluation of multiple variables. The high rate of PJP infection described in this article combined with the known impaired T-cell function post Bendamustine treatment justifies considering all patients for PJP prophylaxis when they receive Bendamustine treatment.

Idiopathic reversible cerebral vasoconstriction syndrome (RCVS).

Reversible cerebral vasoconstriction syndrome is characterised by severe thunderclap headache with associated characteristic transient, multifocal, segmental vasoconstriction of cerebral arteries lasting several weeks to months. We describe a 50-years old woman who presented with a severe sudden onset occipital headache. Neuroimaging revealed segmental vasospasm affecting the intracerebral arteries. The pain improved gradually over the next 6 weeks. Repeat brain MR angiography at 12 weeks showed complete resolution of the segmental narrowing.