Incidental finding of leukaemia in circulating tumour DNA— the importance of a molecular tumour board

As the use of liquid biopsies are increasing across multiple indications in cancer medicine, the detection of incidental findings on circulating tumour DNA is of increasing importance. We report the finding of leukaemia detected in a patient who underwent plasma-based circulating tumour DNA next generation screening as part of a screening liquid biopsy study. A BRAF V600E mutation detected was deemed pathogenic following discussion at a molecular tumour board, and recommendation of further investigations led to the diagnosis of an occult haematological malignancy. We report the importance of molecular tumour board discussion and recommendations in the identification of incidental, pathogenic findings on circulating tumour DNA.