[Intracerebral myeloblastoma developed in a patient with acute monocytic leukemia associated with inv (16) (p13q22)].

A 26 year-old man was diagnosed as having acute monocytic leukemia (M5b: FAB classification) associated with inv (16) (p13q22). Remission induction therapy showed good results, but two years later, he complained visual blurring and revealed right papilledema. Lumbar puncture showed leukemic cell infiltration. Irradiation to the orbita, intrathecal injection of MTX and Ara-C, until the cerebrospinal fluid cleared of leukemic cells, and chemotherapy were performed. One month later, he also complained visual blurring and left papilledema was found. After whole brain irradiation, intrathecal injection and chemotherapy, papilledema disappeared. Then, one year later, paralysis of right lower extremity appeared and brain computed tomography (CT) demonstrated tumor with increased density in the left frontal lobe, which enhanced with contrast material. Analysis of spinal fluid demonstrated abnormal cells. He was treated radiation therapy combined with intrathecal MTX and Ara-C. The patient survives currently three years after diagnosis and remains free of central nervous system disease. Because the patients with inv (16) have a high incidence of CNS involvement, they should be monitored closely with periodic lumber punctures.