The Kabuki Syndrome in 18F-FDG-PET/CT

A 36-year-old man with a history of relapsing infections, cytopenia, and lymphadenopathy was referred for $^{18}$F-FDG-PET/CT to investigate suspected lymphoma. His medical history revealed cardiac surgery during childhood for unknown reasons. Laboratory tests revealed hypogammaglobinemia and elevated soluble IL-2-receptor levels as a sign of inflammation. PET/CT demonstrated generalized lymphadenopathy, splenic and muscle lesions, being more consistent with sarcoidosis than lymphoma. Subsequent excision biopsy of a lymph node and bone marrow biopsy were negative for malignancy. Treatment with high-dose abatacept resulted in complete remission. Genetic testing identified a pathogenic de-novo variant in the KMT2D gene, leading to a diagnosis of Kabuki syndrome.