EBV-driven diffuse large B-cell lymphoma confined to the liver in a patient with a history of idiopathic CD4 lymphocytopenia

Idiopathic CD4+ T-lymphocytopaenia with FLT1 mutation complicated by progressive multifocal leucoencephalopathy and EBV+ polymorphic lymphoproliferative disorder

We describe a unique case of idiopathic CD4+T cell lymphocytopaenia complicated by viral-associated disorders in a patient with a heterozygous FLT1 mutation. A previously healthy woman presented with left-sided neurological deficits. Workup revealed a severe HIV-seronegative CD4+T cell deficiency and white matter brain lesions; brain biopsy confirmed progressive multifocal leucoencephalopathy (PML). Six years later, she represented with a tender mandibular lesion, with pathology diagnostic for EBV+polymorphic post-transplant-like lymphoproliferative disorder. A heterozygous FLT1 P1127L mutation was detected on peripheral blood and mandibular lesion next-generation sequencing. Concern for PML reactivation with rituximab-based therapy and the presence of localised disease led us to offer radiotherapy, resulting in significant symptom relief and marked therapeutic response on repeat imaging.

Idiopathic CD4 Lymphocytopenia: Current Insights

Idiopathic CD4 lymphocytopenia is a condition characterized by low CD4 counts. It is rare and most of the information about this illness comes from case reports. Presentation is usually in the 4th decade of life with opportunistic infections, autoimmune disease or neoplasia. The pathophysiology of this condition is not well understood. Management revolves around treatment of the presenting condition and close follow-up of these patients. This review presents a narrative summary of the current literature on idiopathic CD4 lymphocytopenia.