[Essential thrombocythemia transformed to myelofibrosis with myeloid metaplasia after seven years]

A 29-year-old male was diagnosed as having essential thrombocythemia (ET) in 1975. From that time, his platelet count gradually increased to more than 2 X 10(6)/microliter until 1979. However, his platelet count gradually decreased to less than 6 X 10(5)/microliter in 1985. Also, in 1982, erythroblasts and immature myeloid cells began to appear in the peripheral blood, and the liver and spleen became palpable in 1985. Bone marrow then revealed osteomyelosclerosis. These findings suggested that ET had transformed to myelofibrosis with myeloid metaplasia. Increased hepatosplenomegaly was accompanied by the appearance of ascites in June, 1988, and an esophageal varix ruptured in December of the same year. The varix was resected and the spleen was removed. After the operation, ascites did not recur and his condition became stable. Portal hypertension in this patient was considered to be due mainly to increased blood flow from the enlarged spleen.