Introduction Bone marrow fibrosis is known to be associated with acute myeloid leukemia (AML), most frequently with AML-M7. However, it is rarely seen with acute promyelocytic leukemia (APML). The fibrosis is thought to occur secondary to activation of normal fibroblasts by cytokines secreted by the leukemia cells and often can be reversed with therapy. The overall frequency of fibrosis in patients with APML is unknown. Whether there is a prognostic implication is unknown as well. We report the case of a patient with bone marrow reticulin fibrosis at presentation with a diagnosis of APML that improved with therapy directed at the leukemia.
Case Report A 42-year-old female presented to the emergency room with progressive weakness and fatigue of 1 month's duration. She had no fever, chills, or bruising. She was on no prior medications but had not seen a doctor in over 5 years. Bloodwork was performed, and complete blood count showed a WBC count of 9.11 × 10ˆ3/μL, hemoglobin was 3.9 g/dL, and platelets were 15,000/μL with 33% blasts seen on peripheral smear. Bone marrow aspirate and biopsy were performed. The marrow showed blasts comprised > 90% of all cellular elements, with 50% of the marrow space being fibrotic. Reticulin was markedly increased. The blasts had folded nuclei and scant cytoplasmic granules. Findings were morphologically consistent with M3, a microgranular variant of the FAB classification of AML. Molecular analysis for t(15;17) by fluorescence in situ hybridization analysis was positive in the bone marrow and peripheral blood. Patient was initiated on induction therapy with all-trans retinoic acid (ATRA) and idarubicin. Repeat bone marrow biopsy in 2 months showed a complete remission (CR), with improvement in fibrosis from severe to moderate. She was then treated with two cycles of consolidation therapy with idarubicin. A third bone marrow biopsy continued to show CR pattern with further improvemen in reticulin fibrosis to minimal. The patient began maintenance therapy with daily 6-mercaptopurine, weekly methotrexate, and ATRA daily for 15 days monthly.
Conclusion Bone marrow reticulin fibrosis is commonly associated with AML but rarely seen with APML. This case highlights that, although rare, it may be a secondary process of the leukemia and that therapy directed at the leukemia can help the fibrosis process.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.