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Abstracts
P062
Variant Acute Promyelocytic Leukemia - A Case Report of a Rare Malignancy
Introduction:
Acute promyelocytic leukemia (APL) is rare and accounts for only 5-8% of acute myeloid leukemia and is characterized by t(15;17).Variant APL caused by a variant translocation t(11,17) constitutes only 0.8% of cases of APL and poses a diagnostic and therapeutic challenge.
Methods: Case report:
A 33 year male with history of fatigue and fever was found to have leukocytosis ( Hb- 11.5 gm%, WBC count – 55,000/mm3 and Platelet – 1.4 lakhs/mm3). Clinically he had no lymphadenopathy or organomegaly. Peripheral smear showed increase in promyelocytes and a bone marrow biopsy and aspiration was suspicious of APL. Flow cytometry on bone marrow aspirate revealed clonal promyelocytic cells expressing CD 13,33, myeloperoxidase and negative for HLA DR and CD 34 (ref fig 1). His PML-RARA fusion transcript by RT-PCR in peripheral blood however was negative. Conventional karyotyping revealed t (11;17)(q23;q12∼21) suggesting a possibility of a variant form APML. A break apart FISH for RARA translocation ( ref fig 2 ) was positive and PCR by next generation sequencing revealed ZBTB16:RARA fusion transcript that confirmed “variant APML”.
Results:
Treatment:
He was treated with AML ( 3+7 ) induction with Danorubicin 60 mg/m2‚ÄâDays1-3 and Cytarabine 100 mg/m2 continuous infusion Days 1-7. Due to variant APML differentiating agents were not added. Post induction-1, marrow was not in morphological remission. Re induction was delivered with high dose cytarabine which induced morphological and molecular marrow remission(CR-2). He received an allogenic stem cell transplant from a haplo matched sibling and continues to be in remission after 1 year with 100% chimerism.
Acute promyelocytic leukemia (APL) is rare and accounts for only 5-8% of acute myeloid leukemia and is characterized by t(15;17).Variant APL caused by a variant translocation t(11,17) constitutes only 0.8% of cases of APL and poses a diagnostic and therapeutic challenge.
Methods: Case report:
A 33 year male with history of fatigue and fever was found to have leukocytosis ( Hb- 11.5 gm%, WBC count – 55,000/mm3 and Platelet – 1.4 lakhs/mm3). Clinically he had no lymphadenopathy or organomegaly. Peripheral smear showed increase in promyelocytes and a bone marrow biopsy and aspiration was suspicious of APL. Flow cytometry on bone marrow aspirate revealed clonal promyelocytic cells expressing CD 13,33, myeloperoxidase and negative for HLA DR and CD 34 (ref fig 1). His PML-RARA fusion transcript by RT-PCR in peripheral blood however was negative. Conventional karyotyping revealed t (11;17)(q23;q12∼21) suggesting a possibility of a variant form APML. A break apart FISH for RARA translocation ( ref fig 2 ) was positive and PCR by next generation sequencing revealed ZBTB16:RARA fusion transcript that confirmed “variant APML”.
Results:
Treatment:
He was treated with AML ( 3+7 ) induction with Danorubicin 60 mg/m2‚ÄâDays1-3 and Cytarabine 100 mg/m2 continuous infusion Days 1-7. Due to variant APML differentiating agents were not added. Post induction-1, marrow was not in morphological remission. Re induction was delivered with high dose cytarabine which induced morphological and molecular marrow remission(CR-2). He received an allogenic stem cell transplant from a haplo matched sibling and continues to be in remission after 1 year with 100% chimerism.
Publisher
John Wiley & Sons; Hoboken, USA
Source Journal
American Journal of Hematology
2022 Wiley Periodicals LLC.
