Ph-negative isolated myeloid sarcoma with NPM1 gene mutation in adolescent with Ph-positive chronic myeloid leukemia in remission after treatment with allogeneic bone marrow transplantation and imatinib mesylate

Myeloid sarcoma derived from the gastrointestinal tract: A case report and review of the literature

Myeloid sarcoma is a type of malignant neoplasm composed of myeloblasts that locates extramedullary. The present study reports the case of a 31-year-old female who presented with upper abdominal pain, melena, vomiting and jaundice. The abdominal computed tomography revealed a mass in gastric antrum area and possible infiltration of the duodenum, gallbladder and head of the pancreas, with possible retroperitoneal lymph node metastasis. The tumor grew quickly and led to serious obstructive jaundice. New masses developed in the bilateral orbits and left breast within 2 months of admission. The pathological results of the gastroscopic biopsy and the fine-needle biopsy of the breast revealed myeloid sarcoma. Transhepatic cholangial drainage, radiotherapy and chemotherapy were administered, but the disease reoccurred and became resistant to chemotherapy, so salvage allogenetic peripheral blood stem cell transplantation was performed. The disease relapsed at 5 months post-transplantation, and chemotherapy and donor lymphocytes transfusions were then administered. The patient declined further treatment and succumbed to disease on May 19, 2015. The present study could improve the understanding of myeloid sarcoma and provide a reference for standardized and individualized treatments for this disease.

Simultaneous detection of mutations and copy number variation of NPM1 in the acute myeloid leukemia using multiplex ligation-dependent probe amplification

The NPM1 gene encodes nucleophosmin, a protein involved in multiple cell functions and carcinogenesis. Mutation of the NPM1 gene, causing delocalization of the protein, is the most frequent genetic lesion in acute myeloid leukemia (AML); it is considered a founder event in AML pathogenesis and serves as a favorable prognostic marker. Moreover, in solid tumors and some leukemia cell lines, overexpression of the NPM1 gene is commonly observed. Therefore, the purpose of this study was to develop a new method for the detection of NPM1 mutations and the simultaneous analysis of copy number alterations (CNAs), which may underlie NPM1 gene expression deregulation. To address both of the issues, we applied a strategy based on multiplex ligation-dependent probe amplification (MLPA). A designed NPM1mut+ assay enables the detection of three of the most frequent NPM1 mutations: A, B and D. The accuracy of the assay was tested using a group of 83 samples from Polish patients with AML and other blood-proliferative disorders. To verify the results, we employed traditional Sanger sequencing and next-generation transcriptome sequencing. With the use of the NPM1mut+ assay, we detected mutations A, D and B in 14, 1 and 0 of the analyzed samples, respectively. All of these mutations were confirmed by complementary sequencing approaches, proving the 100% specificity and sensitivity of the proposed test. The performed sequencing analysis allowed the identification of two additional rare mutations (I and ZE). All of the mutations were identified exclusively in AML cases, accounting for 25% of those cases. We did not observe any CNAs (amplifications) of the NPM1 gene in the studied samples, either with or without the mutation. The presented method is simple, reliable and cost-effective. It can be easily introduced into clinical practice or developed to target both less-frequent mutations in the NPM1 gene and other cancer-related genes.

Philadelphia chromosome-negative acute myeloid leukemia with 11q23/MLL translocation in a patient with chronic myelogenous leukemia

Although defined by the presence of t(9;22), chronic myelogenous leukemia (CML) can have other concurrent additional cytogenetic changes, especially during disease progression. Additional chromosomal changes (ACAs) in CML often occur in Philadelphia chromosome (Ph)-positive cells and are associated with disease acceleration and treatment resistance. Occasionally chromosomal changes occur in Ph-negative cells and this phenomenon is often transient and does not correlate with disease progression. Very rarely myelodysplastic syndrome or acute leukemia can develop in Ph-negative cells. In this study, we report an unusual case of acute myeloid leukemia (AML) with 11q23/MLL translocation emerging from Ph-negative cells in a patient with CML.