[Syndrome of inappropriate secretion of antidiuretic hormone in a patient with myeloid antigen positive acute lymphoblastic leukemia after systemic chemotherapy including vincristine].

We report a case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after the patient had received several anti-cancer drugs, including vincristine (VCR), in a patient with myeloid antigen positive acute lymphoblastic leukemia (My(+)-ALL). A 53-year-old woman presented at the hospital complaining of high-grade fever and general lassitude. Further examination revealed that she had My(+)-ALL. On admission, she was treated with anti-cancer drugs, including VCR. On day 24, after the first administration of VCR, a conscious disturbance suddenly occurred and she was diagnosed with SIADH. A plain head CT scan showed a low density lesion through the gray matter to the white matter in the bilateral occipital lobe, as well as diffuse swelling of the cerebrum. This was not seen on the follow up CT scan, and we concluded that it had been a transient abnormal finding due to SIADH. She achieved complete remission after induction chemotherapy and 3 added courses of consolidation chemotherapy. VCR was also administered 4 times in the second consolidation chemotherapy, but hyponatremia did not occur. This case suggests that a head CT scan is a useful procedure for the diagnosis and monitoring of SIADH, and that VCR may still be used in a patient who has suffered from VCR-induced SIADH.