( 1 ) patients , adult of more than 40 years of age , ( 2 ) relatively acute fatal course ( about 20 to 100 days ) , ( 3 ) continued pancytopenia in the peripheral blood , ( 4 ) so-called blast cells , occasionally showing accumulation , according to the length of total duration , in addition to overwhelming predominance of atypical megakaryocytic cells in the bone marrow , and ( 5 ) an increased tendency of fibrillosis in the interstitium of the bone marrow corresponding to the more or less prolonged duration of the course .
C0030312
pancytopenia
C0005953
bone marrow