Abstract
We have experienced 15 cases widely categorized in atypical leukemia, and tried to classify these cases into following 4 groups.
Group 1. Leukemic change from preleukemic states. Four in 15 cases developed from the preleukemic stages such as aplastic anemia, sideroblastic anemia, and thrombocytosis.
Group 2. Specific clinical features during the course of leukemia. In this group, the combination with CNS leukemia, leukemic pleuritis, and myeloblastoma were involved. We had six such cases.
Group 3. Alternation of main leukemic cells during the course of leukemia. Two cases were observed in erythroleukemia and myelomonocytic leukemia.
Group 4. The clinical features of so-called atypical leukemia. There were 3 cases called low percentage leukemia or smoldering leukemia.
Fifteen cases of atypical leukemia were classified into 4 groups as described above and discussed in detail.
