[Myelodysplastic syndrome (RAEB-T) occurring after adjuvant chemotherapy for colon and rectum cancers]

A 67-year-old man was admitted to our hospital because of bleeding tendency and high fever. The patient had a past history of gastrectomy and transverse colectomy for cancer of transverse colon at age 57, and rectum resection for rectum cancer at age 59. After these operations, Tegafur 645 g, MMC 56 mg, and Ara-C 560 mg were administered for about 6 years. Hematological examinations revealed hemoglobin of 7.7 g/dl, white cell count of 9,500/microliters with 8% myeloblasts, and platelet count of 7,000/microliters. A diagnosis of myelodysplastic syndrome (RAEB-T) was made from the finding of bone marrow smear, which showed 28% myeloblasts, and neutrophils and megakaryocytes with morphologically abnormal nuclei and cytoplasms. Chromosomal banding study of the bone marrow cells revealed -5, -8, 7q- in all analyzed cells. These findings suggest that the preceding adjuvant chemotherapy is probably related to the occurrence of myelodysplastic syndrome.