PMC9277000_01
(A) Axial T2-weighted (right image) and apparent diffusion coefficient (ADC, left image) MRI sequences. A right frontal soft tissue mass is patent, hypo-intense on T2 and with low ADC values (500), which likely represent high cellularity. (B) Axial contrast-enhanced T1-weighted images with fat saturation at two levels show bilateral masses, right frontal and left parietal, with homogeneous enhancement. (C) Unenhanced CT scan centered in the right frontal mass shows spontaneous hyper-density in the parenchymal window (right image), also typical of hyper-cellular tumors. Bone window (left image) shows erosive changes within the subjacent bone. Findings are consistent with myeloid sarcoma. MRI scans were taken in December 2020.
fped-10-875510-g0001.jpg
PMC9277000_01_fped-10-875510-g0001.jpg
F1
The findings of additional MRI and computerized tomography (CT) scans were consistent with myeloid sarcoma (Figure 1).
Schematic representation of the most important events in the diagnosis, treatment and follow-up of the clinical case. CUN, Clinica Universidad de Navarra; US, Ultrasound Study; BM, Bone Marrow; NOPHO, Nordic Society of Pediatric Hematology and Oncology; AML, Acute Myeloid Leukemia; NGS, Next Generation Sequencing.
fped-10-875510-g0002.jpg
PMC9277000_01_fped-10-875510-g0002.jpg
F2
The skin lesions evolved to hyperpigmented residual lesions with treatment, but the bone lesions persisted without significant reduction despite the intensive treatment regimen (Figure 2).
Follow-up of minimal residual disease (black) by qPCR and treatment plan (grey). RBM15::MKL1 relative expression and administered chemotherapy following the NOPHO-DBH AML 2012 Dates highlighted (bold underlined) indicate data points in which multiparametric flow cytometry analyses were evaluable. Protocol from diagnosis to patient death. MEC, (mitoxantrone in first course) and ADxE (cytarabine, liposomal daunorubicin, etoposide): induction course, HAM (High-dose cytosine arabinoside and mitoxantrone): consolidation course, CLO (clofarabine) and FLA (fludarabine): salvage therapy, HSCT, Hematopoietic stem cell transplantation.
fped-10-875510-g0003.jpg
PMC9277000_01_fped-10-875510-g0003.jpg
F3
The tumor fusion gene was detectable at all follow up points, always by performing a bone marrow biopsy (Figure 3). MRD monitoring by multiparametric flow cytometry and imaging indicated persistence of extramedullary disease in all time points evaluable. Many aspirate samples in this patient were not evaluable and samples were extremely difficult to obtain and analyze, so that only limited time points were available and positive for extramedullary disease (Figure 3).
PMC9277000_02