Institution: The University of Texas MD Anderson Cancer Center
Additional authors:Bing Bai, Gary Lu, Shimin Hu, C. Cameron Yin
Session: AML with recurrent genetic abnormalities Part I
HISTORY
The patient was a 56-year-old Hispanic man who initially presented with mouth ulcers, eye infection, and fatigue in June 2008. He was found to be cytopenic with a white cell count of 5.9 K/uL, hemoglobin of 8.5 g/dL, and platelet count of 30 K/uL, with 45% circulating blasts. A bone marrow examination performed on June 25, 2008 revealed acute myeloid leukemia with minimal differentiation. The patient was admitted to a local hospital, and was treated with induction regimen with daunorubicin and cytarabine (7+3). A repeat bone marrow performed on July 30, 2008 showed no evidence of leukemia. The patient declined further chemotherapy. He remained well until November 2008 when a bone marrow examination revealed relapsed disease. He was treated with a salvage regimen with fludarabine, cytarabine, idarubicin, and G-CSF (FLAG), and came to our institution for further treatment options.
Upon presentation at our institution, his white cell count was 6.9 K/uL, hemoglobin 12.8 g/dL, and platelet count 355 K/uL, with a normal differential count. His serum lactate dehydrogenase level was 581 IU/L, and his serum b2-microglobulin level was 1.8 mg/L. There was no palpable hematosplenomegaly or lymphadenopathy. Bone marrow biopsy showed no morphologic or immunophenotypic evidence of AML. He received consolidation therapy with high-dose cytarabine in December 2008. He then received matched related stem cell transplantation in February 2009. However, the disease relapsed again in April 2009. The t(1;3)(p36;p21) was detected at the time of relapse. The patient decided not to receive any further treatment for AML, and he died 11 months after initial diagnosis.DETAILS
A bone marrow examination performed on June 25, 2008 revealed a hypercellular marrow with trilineage hypoplasia, dysgranulopoiesis, dyserythropoiesis, and 80% blasts. The blasts varied from small to intermediate-sized to large with fine chromatin, prominent nucleolus, and scant to moderate amount of cytoplasm.
IMMUNOHISTOCHEMISTRY AND FLOW CYTOMETRY
The blasts were negative for myeloperoxidase by cytochemistry. Immunohistochemical studies showed that the blasts were positive for CD34 and CD117, and negative for CD3, CD10, CD20, CD68, myeloperoxidase and terminal deoxynucleotidyl transferase. Flow cytometry immunophenotypic analysis of the bone marrow aspirate material revealed that the blasts were positive for dim CD4, CD11b, CD13, dim CD33, CD34, CD38, CD45, dim CD64, CD117, CD123 and HLA-DR, and were negative for CD2, cytoplasmic CD3, CD5, CD7, CD10, CD14, CD15, CD16, CD19, CD20, CD41, CD56, terminal deoxynucleotidyl transferase and myeloperoxidase.
CYTOGENETIC FINDINGS
Cytogenetic study demonstrated 46,XY,t(1;3)(p36;p21)[20].
MOLECULAR FINDINGS
None.
INTERESTING FEATURES
Cytogenetic abnormalities have been regarded as one of the most important prognostic factor in AML. Clonal chromosomal aberrations have been detected in over 50% of AML, with +8, -7/del(7q), +21, -5/del(5q) being the most common. Hematopoietic neoplasms associated with t(1;3)(p36;p21) is a rare entity and has only been described in 2 cases of AML, both were classified as acute promyelocytic leukemia. In both cases, t(1;3) presented as part of complex cytogenetic abnormalities. We report the first case of an AML with t(1;3)(p36;p21) as the sole cytogenetic abnormality in a 56-year-old Hispanic man with immature phenotype, high blast count, resistance to multiple chemotherapy, and a poor clinical outcome. The t(1;3) was detected at initial presentation and was not associated with prior exposure to chemotherapy or radiation therapy.
PROPOSED DIAGNOSIS
t(1;3)(p36;p21) as the sole clonal abnormality in refractory acute myeloid leukemia
CONSENSUS DIAGNOSIS
Acute myeloid leukemia with t(1;3)(p36;p21)