Astrocytoma (CNS WHO grade 4), IDH-mutant with co-occurrence of BRAF p.V600E mutation, and homozygous loss of CDKN2A.

Molecular alterations nowadays play a crucial role in the diagnosis of brain tumors. Some of these alterations are associated with outcome and/or response to treatment, including sequence variants of isocitrate dehydrogenase (IDH) at position p.R132 or p.R172. Such IDH variants have so far been described in histone H3-wildtype primary brain tumors only in adult-type diffuse gliomas and are associated with a better outcome compared to their IDH-wildtype counterpart, the glioblastoma. Moreover, homozygous loss of CDKN2A and/or CDKN2B in IDH-mutant astrocytomas shortens the median overall survival regardless of histological features of malignancy. Such tumors are therefore considered to be aggressive and graded as WHO central nervous system (CNS) grade 4 lesions. The coexistence of an IDH-sequence variation and a BRAF p.V600E alteration has only rarely been described in diffuse astrocytomas. Due to the small number of cases, little is known about such neoplasms in terms of clinical behavior and response to treatment. Herein we describe the first case, to our knowledge, of an astrocytoma (CNS WHO grade 4), IDH-mutant, and BRAF p.V600E-mutant with homozygous deletion of CDKN2A. Pathologists should be aware that such an expression profile does exist even in WHO CNS grade 4 astrocytomas, IDH-mutant, and are encouraged to test for the BRAF p.V600E sequence variant as such an alteration may provide additional treatment options.

[A man in his thirties with recurrent brain abscesses] / En mann i 30-årene med gjentatte hjerneabscesser.

BACKGROUND: Brain abscess is a life-threatening condition. Congenital cardiovascular malformations can create right-to-left shunting and be an underlying cause. CASE PRESENTATION: A young man was admitted due to headache and deteriorating general condition. He had a history of a surgically treated brain abscess 19 years earlier. Investigations now showed a new brain abscess. The patient was operated and received a peripherally inserted central catheter in his left arm for antibiotic treatment. A chest X-ray showed abnormal positioning of the catheter lying in a persistent left superior vena cava. One day later he experienced headache and photophobia. MRI showed reoccurrence of the brain abscess and he was reoperated. Persistent left superior vena cava was considered to be the cause of the brain abscesses and he underwent endovascular embolisation and placement of a vascular plug in his left superior vena cava. INTERPRETATION: The oxygen-rich pulmonary circulation and its immune system make it difficult for anaerobic bacteria to pass to the arterial side. In most cases persistent left superior vena cava drains into the right atrium and is asymptomatic. In 10 % of patients the persistent left superior vena cava drains directly to the left atrium and gives a right-to-left shunt. This may cause arterial bacteraemia and brain abscesses.