FDG PET/CT Demonstrated Precursor B-cell Lymphoblastic Lymphoma in a Pediatric Patient With Hemophilia B.

A 4-year-old boy with history of hemophilia B presented with increasingly enlarged scalp masses. Although they were initially thought as hematomas, unresponsiveness to the therapy lead to suspicion of malignancy, which prompted FDG PET/CT. The FDG PET/CT images demonstrated increased FDG uptake in the scalp masses and cervical lymph nodes. The pathology from the left scalp mass and the left cervical lymph nodes revealed precursor B-cell lymphoblastic lymphoma.