A case of intravascular large B cell lymphoma with brain involvement mimicking progressive multifocal leukoencephalopathy.

Intravascular large B-cell lymphoma (IVLBCL) is a very rare form of extranodal lymphoma, characterized by the proliferation of neoplastic B cells within the lumen of small vessels. Due to its high aggressivity, for years the prognosis had been really poor with only anectodical cases of remission after traditional chemotherapy. More recently, new therapeutic protocols allowed a significant increase in overall survival. It can virtually involve every organ, being skin and central nervous system the most affected. The clinical presentation is often unspecific and insidious; therefore, diagnosis can be challenging. Tissue biopsy, in particular random deep skin biopsy, is the gold standard for definitive diagnosis. We describe the case of a 58-year-old woman with a previous diagnosis of myelofibrosis, who presented with a rapidly progressive neurological deterioration and a brain MRI suggestive of Progressive Multifocal Leukoencephalopathy. Due to the absence of BK and JC viruses in cerebrospinal fluid and the presence of severe myalgias and subcutaneous nodules, a skin and muscle biopsy was performed, allowing diagnosis of IVLBCL. We describe the diagnostic pitfalls of this case, briefly reviewing existing literature about IVLBCL.

PRES-like leukoencephalopathy presenting with status epilepticus associated with Brentuximab Vedotin treatment.

Posterior Reversible Encephalopathy Syndrome (PRES) is characterized by acute neurological symptoms with typical imaging features, primarily in the territories of the brain supplied by the posterior circulation, probably due to vasogenic edema. Both clinical and imaging features are generally reversible. We report a 13-year-old girl affected by Nodular Sclerosis Classical Hodgkin Lymphoma stage IIIB into complete remission, with a recurrence and autologous bone-marrow transplantation, who has been treated with an anti-CD30 monoclonal antibody, brentuximab-vedotin. The girl has suddenly presented a convulsive status epilepticus, that needed intubation and sedation. Therefore, an IV therapy with levetiracetam was started. Furthermore, the girl has presented high blood pressure and reduced kidney function. Brain MRI demonstrated a diffuse PRES-like disease, that went into regression after the first week. After another week, the girl presented a new prolonged generalized tonic clonic convulsive episode, that needed intubation and sedation and an association of clobazam and levetiracetam: a new brain MRI showed a recurrence of PRES-like lesions in addition to some signs of leukoencephalopathy with brain lactate accumulation on 1H-MRS, due to cerebral energetic failure. The girl also presented a refractory arterial hypertension. After 45 days of ICU hospitalization the patient has been discharged and followed up with neurological examinations. Brain MRI and brain 1H-MRS, 5 months after patient's discharge, showed incomplete regression of cerebral white matter signal abnormalities with MRS normalization.