Spontaneous Remission In A Patient With Acute Myeloid Leukemia Leading To Undetectable Minimal Residual Disease
Helbig, D., Quesada, A. E., Xiao, W., Roshal, M., Tallman, M. S., & Knorr, D. A. (2020). Spontaneous Remission in a Patient With Acute Myeloid Leukemia Leading to Undetectable Minimal Residual Disease. Journal of hematology, 9(1-2), 18–22. https://doi.org/10.14740/jh606
View Original Source →Abstract
Although rare, spontaneous remission (SR) of acute myeloid leukemia (AML) has been reported in the literature, the underlying mechanisms driving remission remain unknown. However, it is most commonly associated with a preceding severe infection. We present a case of a 40-year-old man with no past medical history who presented to our hospital with severe left hip pain and fevers and was found to have AML. Chemotherapy was delayed because the patient required extensive debridement and fasciotomy of his left hip and a prolonged course of antibiotics. After his acute illness had stabilized, a repeat bone marrow biopsy was performed which showed no abnormal myeloid blasts and resolution of his original cytogenetic and molecular abnormalities. At the time of this writing, our patient remains in remission with undetectable minimal residual disease (MRD), now 14 months from his initial diagnosis of AML.
Case Details
Disease Location
Bone marrow
Personal Characteristics
40-year-old man
Clinical Characteristics
Presented with severe left hip pain and fevers that started abruptly the day prior. On physical exam, he had significant erythema and tenderness to the left hip area. CT scan demonstrated an acute tear of the left gluteal medius muscle. Initial blood cultures grew methicillin-susceptible staphylococcus aureus (mssa) so the patient was initiated on broad-spectrum antibiotics. Initial labs also revealed pancytopenia, anemia, and thrombocytopenia. Lactate dehydrogenase (ldh) and creatine kinase were elevated. Bone marrow biopsy revealed a hypercellular marrow (70-80%) with sheets of blasts and scattered small islands of erythroid elements and reduced megakaryocytes. Flow cytometry of the bone marrow aspirate revealed blasts positive for CD34 and CD117 (partially), comprising 80% of the total cells. Peripheral blood identified a CD34-positive blast population (3.7% of total wbcs) with abnormal (p.arg172lys) mutations. Based on the above, a diagnosis of acute myeloid leukemia (aml) was made. The patient continued to experience daily fevers and required frequent transfusions of red blood cells. He also continued to complain of severe left hip pain despite broad-spectrum antibiotics and antifungal coverage. MRI of the left hip revealed an underlying fluid collection and possible abscess within the gluteus medius muscle. Drainage by interventional radiology was attempted but unsuccessful. A repeat MRI several days later showed worsening myositis, myonecrosis, and fasciitis so the patient underwent extensive debridement and fasciotomy
Remission Characteristics
While waiting to begin induction chemotherapy, his fevers resolved and his peripheral blood counts improved. A repeat bone marrow biopsy was performed 3 weeks from the original bone marrow biopsy (day 21), revealing a normocellular marrow (60-70%) with trilineage maturing hematopoiesis with no overt increase in blasts. Flow cytometry identified a small abnormal myeloid blast population comprising only 0.08% of the total cells analyzed. A repeat bone marrow was performed a month later (day 49) as an outpatient, which showed a normocellular marrow (50-60%) with trilineage maturing hematopoiesis with no abnormal myeloid blasts identi- fied by flow cytometry
Treatment & Mechanisms
Proposed Remission Mechanisms
Immune-mediated caused secondary to a preceding severe infection
Clinical Treatment
Borad-spectrum antibiotics, antifungals, unsuccessful drainage.
Non-Clinical Treatment
None reported