B-cell lymphoblastic lymphoma which is a type of non-Hodgkin lymphoma is rather uncommon in children. Focal changes in bones in the course of non-Hodgkin lymphoma are mostly secondary changes and their primal location in a bone is rare. PBL (primary bone lymphoma) mainly concerns a thighbone and a tibial bone; the primary location in jaw bones is quite sporadic. In diagnostics, there is mainly magnetic resonance, medical scan (tomography), and above all – histopathological test. There is also chemotherapy by choice, and primary location in a jaw or a mandible significantly advances the prognosis. The aim of the work is to introduce a patient who was definitively diagnosed B-cell lymphoblastic lymphoma from the early B-cells. The girl reported to Laryngological Clinic, Dental Surgery Clinic for Children, Oncological Clinic of Children’s Memorial Health Institute. The cause of the visit was an elevation on the right side of a nose base, present for two months and misdiagnosed by doctors as a post-traumatic swelling in this region. After introducing laboratory and scan diagnostics and taking biopsy from the lesion, a final conclusion was made. Also, a proper treatment according to the protocol for B-cell lymphoblastic lymphoma was introduced. Non-specific B-cell lymphoma picture, as mentioned in the described case, specifically due to location in a jaw bone and a slow pace of growing, may both constitute huge diagnostic problems and deteriorate prognosis. Therefore, it is important to take into account also lymphoma – in such location of a lesion. Moreover, it is worth remembering that the final diagnosis may only be passed on the basis of histopathological examination.