Rare intravascular large B-cell lymphoma (IVLBCL) can cause atypical intracerebral haemorrhage and mislead diagnostics.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of non-Hodgkin's lymphoma. Common neurological symptoms are cognitive impairment and dementia. Only a few cases have been published reporting intracranial haemorrhage due to IVLBCL. We present a case of a female patient in her late 60s who presented with an atypical intracerebral haemorrhage as the first major complication of an IVLBCL. The patient's condition declined rapidly. She died several weeks later due to haemorrhagic shock. The definitive diagnosis was achieved postmortem. Due to aggressive disease progression, the diagnosis of IVLBCL is still challenging and can therefore lead to incorrect or delayed treatment, especially in cases of unusual manifestations like lobar intracranial haemorrhage.