Behavioral variant frontotemporal dementia with pathogenic variant in presenting as dementia with Lewy body disease.

A 75-year-old Chinese American man presented to behavioral neurology clinic for a second opinion of dementia with Lewy body disease (DLB). The clinical manifestations met the criteria for a probable DLB diagnosis. Yet, in-depth evaluation unveiled clinical history, family history, and neuroimaging evidences that suggested a diagnosis of behavioral variant frontotemporal dementia (FTD). A heterozygous pathogenic variant in the microtubule-associated protein Tau () was identified through genetic testing and confirmed the diagnosis of autosomal dominant -related FTD. This case is the first reported instance of -related FTD presenting with well-formed visual hallucinations in an elderly Chinese American.