Early diagnosis of acute promyelocytic leukemia (APL) depends primarily on morphological recognition before the presence of t(15;17) or PML-RAR gene rearrangement is confirmed. But the diagnosis is difficult to be made, if typical APL morphologic features are not found. Here, we describe a 32- year old man who had been diagnosed as APL. He relapsed with AML M1 like phenotype, lacking the typical features of APL. At relapse, t(15;17) and PML-RAR alpha gene rearrangement were detected. After 14 days of chemotherapy and all-trans retinoic acid, the phenotype changed from the AML M1 like features to the typical hypergranular APL. Awareness of atypical morphologic subtypes found in APL is important. And identification of t(15;17) or PML/RAR alpha rearrangement will be helpful in diagnosis of atypical APL.
Diagnosis ; Drug Therapy ; Early Diagnosis ; Gene Rearrangement ; Leukemia, Promyelocytic, Acute* ; Phenotype ; Recurrence* ; Tretinoin

BACKGROUND: The origin of hematologic malignancies has been known to be monoclonal. In most cases, the same or obviously related chromosomal abnormliaties are found and cytogenetically unrelated clones are uncommon. We evaluated the prevalence and clinical significance of patients with cytogenetically unrelated clones in hematologic malignancies. METHODS: Included in the study were 324 patients who had been diagnosed with the following hematologic malignancies at Ewha Womans University, Mokdong Hospital: AML (93 cases), MDS (27), CML (51), myeloproliferative disorder (38), acute biphenotypic leukemia (8), ALL (44), CLL (9), multiple myeloma (MM, 40), and Non-Hodgkin's lymphoma with bone marrow involvement (14). RESULTS: The overall prevalence of hematologic malignancies with cytogenetically unrelated clones at diagnosis was 0.9% (3/324). Of AML patients, 1.1% (1/93) had unrelated clones, CLL 11.1% (1/9), and MM 2.5% (1/40). The other hematologic malignancies did not show cytogenetically unrelated clones. The AML patient had add(11)(q23)/add(1)(p36.3); the CLL patient had +12/ del(13)(q22); and the MM patient had +der(1)t(1;13)(p12;q12), -13/-X, +5, +7, -8, -12, -13, add(14) (q32), +15, -16, +19, -20, -22, -22. We also detected an unrelated clone of trisomy 8 in Philadelphia chromosome negative cells from a CML patient who was treated with imatinib mesylate. CONCLUSIONS: Hematologic malignancies with cytogenetically unrelated clones are uncommon. This report highlights the importance of the conventional chromosomal analysis in that an unrelated clone in philadelphia chromosome negative cells may be detected in a CML case.
Bone Marrow ; Clone Cells* ; Diagnosis ; Female ; Hematologic Neoplasms* ; Humans ; Leukemia, Biphenotypic, Acute ; Lymphoma, Non-Hodgkin ; Mesylates ; Multiple Myeloma ; Myeloproliferative Disorders ; Philadelphia Chromosome ; Prevalence ; Trisomy ; Imatinib Mesylate