RESUMEN
Lymphoblastic lymphoma-leukemia (LBLL) most commonly presents with mediastinal masses (50-75%), while pleural and pericardial effusion may also be present. Lymphadenopathy usually in the neck, axilla or supraclavicular regions, is considered as another typical presentation of the disease. This is a case report of a six-year-old boy with unusual huge enlargement of maxilla, mandible and soft palate as well as gingival hypertrophy which led to secondary respiratory and feeding difficulties. Morphologic and flowcytometric evaluation of bone marrow aspiration showed that it was a T cell type acute leukemia which may be due to dissemination of a lymphoblastic lymphoma and considered as a case of lymphoma-leukemia. After appropriate treatment, the symptoms of the patient relieved significantly and he is in complete remission for about one year.