[B precursor lymphoblastic leukemia/lymphoma manifested at onset as hemophagocytic syndrome].

A 20 year-old male patient was admitted to our department for the treatment of recurrence of fever and pancytopenia developed despite of temporal remission of hemophagocytosis syndrome that had been treated with large doses of methylprednisolone in our hospital. Superficial lymph nodes were not palpable. CT scan and echography revealed neither findings of splenohepatomegalia or enlargement of intraabdominal lymph nodes. Bone marrow aspiration showed an increase of histiocytes, the cells phagocytizing erythrocytes and platelets, and a negative test for peroxidase stain. Analysis of surface antigens showed that 11.3% of cells were blast cells positive for CD10, CD19, CD20, CD34 and TdT. Bone marrow biopsy revealed a localized increase in tumor cells positive for L26, CD10 and negative for UCHL-1. Because of the absence of detectable tumor masses and the difficulty in differentiating between malignant lymphoma and lymphatic leukemia, we diagnosed the condition as B precursor lymphoblastic leukemia/lymphoma. If diagnosed with malignant lymphoma preceded by hemophagocytic syndrome(LAHS), he might have a rare type of LAHS-associated malignant lymphoma since histological examination did not reveal diffuse large cell lymphoma, a condition found in most patients with LAHS-associated malignant lymphoma. Whereas if diagnosed as ALL, he was the first adult patient with ALL with HPS at onset as far as we know. In any of these possibilities, the case was considered rare.