Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Treatment-related myelodysplastic syndrome (t-MDS) and acute myelogenous leukemia (t-AML) are now well established as complications of cytotoxic chemotherapy. We experienced a 28-yr-old female patient who developed t-MDS/t-AML with characteristic chromosomal abnormalities including 11q23 chromosomal rearrangement following high-dose chemotherapy with autologous stem cell transplantation (ASCT) for non-Hodgkin's lymphoma. The patient was admitted with bulky abdominal masses of B cell lineage non-Hodgkin's lymphoma. After 2 cycles of systemic chemotherapy of the Vanderbilt regimen, the patient underwent ASCT with high dose chemotherapy of the BEAC regimen. She also received radiation of 48 Gy for the residual periportal lymphadenopathy. The initial cytogenetic analysis of the infused mononuclear cells revealed a normal karyotype. Twenty two months after the ASCT, pancytopenia was noted and her bone marrow aspirate showed dysplastic hemopoiesis with myeloblasts up to 12% of nonerythroid nucleated cells. The patient was diagnosed as t-MDS (refractory anemia with an excess of blasts). Cytogenetic analysis showed complex chromosomal abnormalities including 11q23 rearrangement, which is frequently found in topoisomerase II inhibitor-related hematologic malignancies. Four months later, it was noted that the t-MDS had evolved into an overt t-AML. Cytogenetic analysis showed an evolving pattern with more complex abnormalities. The patient was treated with combination chemotherapy, but her leukemic cells were resistant to the therapy.
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PMID:A case of treatment-related myelodysplastic syndrome and acute myelogenous leukemia following high-dose chemotherapy with autologous stem cell transplantation for non-Hodgkin's lymphoma. 1217 56

Mixed-phenotype acute leukemia is a rare form of leukemia that is associated with a poor prognosis. Most cases of mixed-phenotype acute leukemia are de novo. However, therapy-related mixed-phenotype acute leukemia can occur, and are often associated with exposure to topoisomerase-II inhibitors and alkylating agents. There are no known treatment guidelines for therapy-related mixed-phenotype acute leukemia. We present a patient with T/myeloid mixed-phenotype acute leukemia secondary to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone R-CHOP chemotherapy for primary cutaneous diffuse large B-cell lymphoma. The patient's leukemic cells express CD34, an immaturity marker, CD3, a T-cell marker, and myeloperoxidase, a myeloid marker, and her history of chemotherapy for previous lymphoma supports the diagnosis of therapy-related T/myeloid mixed phenotype acute leukemia. Clinicians should be aware that this entity could be associated with R-CHOP chemotherapy. Given the complexity in diagnosis, and lack of treatment guidelines, a further understanding of the pathological and genetic principles of therapy-related mixed-phenotype acute leukemia will assist in future efforts to treat and categorize these patients. Mixed phenotype acute leukemia is a rare entity that accounts for two to five percent of all acute leukemias. Therapy- related mixed phenotype acute leukemia is an exceedingly rare hematological neoplasm that accounts for less than one percent of acute leukemias. We describe a case of therapy-related T/myeloid mixed phenotype acute leukemia following rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone R-CHOP chemotherapy for primary cutaneous diffuse large B-cell lymphoma DLBCL. The patient is a 63-year-old female who presented with several cutaneous nodules diagnosed as primary cutaneous DLBCL. The patient received R-CHOP chemotherapy and achieved remission. She remained in remission for four years until she presented with dyspnea, night sweats, weakness, and diffuse lymphadenopathy. Her presentation was initially concerning for recurrent lymphoma; however, a bone marrow biopsy and aspirate and a lymph node biopsy revealed a distinct blast population consistent with T/myeloid mixed phenotype acute leukemia T/M-MPAL. Given the patient's history of previous chemotherapy exposure, our patient represents a case of therapy-related T/myeloid mixed phenotype acute leukemia t-MPAL.
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PMID:THERAPY-RELATED T/MYELOID MIXED PHENOTYPE ACUTE LEUKEMIA IN A PATIENT TREATED WITH CHEMOTHERAPY FOR CUTANEOUS DIFFUSE LARGE B CELL LYMPHOMA. 2698 62