INTRODUCTION:The posterior reversible encephalopathy syndrome (PRES) presents as focal neurological symptoms associated with neuroimaging of brain edema, frequently evolving toward remission. It typically manifests as a transient episode of encephalopathy, seizures, and visual disturbances within specific patient populations. Originally described in patients with autoimmune conditions, it also occurs in solid organ transplant (SOT) recipients, possibly due to the effect of immunosuppressive drugs (ISDs). [1] In these conditions, presumed damage to the blood-brain barrier results from endothelial dysfunction caused by exposure to the toxic effects of these agents, or is precipitated by cerebrovascular dysregulation following acute hypertension. [2]Common brain magnetic resonance image (MRI) patterns associated with PRES include vasogenic brain edema in the white matter, with a dominant parieto-occipital pattern, bilateral watershed pattern, or superior frontal sulcus pattern. However, atypical localizations such as frontal, temporal, basal ganglia, brainstem, or cerebellar involvement can also occur. Recently, a bilateral occurrence of basal vasogenic brain edema outlining the lentiform nucleus, known as the ’lentiform fork sign’ (typically described as a reliable sign of uremic encephalopathy), has been identified in patients experiencing PRES without metabolic disturbances. [4-7]In this report, we present a case of a recent bilateral lung and liver transplant recipient with a diagnosis of cystic fibrosis who experienced his first-ever seizure episode, reflecting PRES with an atypical neuroimaging pattern, including the lentiform fork sign.