Primary lymphoma of bone in children: Three case reports and literature review

Primary lymphoma of the bone (PLB) is a rare form of extranodal lymphoma. The clinical features and imaging findings of PLB are not specific. Histological examination and immunophenotyping is the gold standard for diagnosis. We reported three cases, all diagnosed with B-cell lymphoblastic lymphoma. The first patient is a 4-year-old boy with 6 months history of PLB. Lytic permeative areas with soft-tissue masses showed on imaging. A mutation of the FANCA gene of this patient was detected through whole exome sequencing (WES). The second patient is a 17-year-old boy with multiple areas of pain over 2 months. Flurodeoxyglucose positron emission tomography/computed tomography showed that the density of multiple bones was slightly increased. WES revealed a heterozygous splice site variation in the SBDS gene. The third patient is a 3-year-old boy with swelling and pain of the left knee joint and fever for 43 days. An oval like lesion area appeared on imaging. The display of case details helps to diagnose and understand PLB. The correlation between the occurrence and progression of the disease and FANCA gene and SBDS gene mutations remains to be studied.