Cytogenetic and molecular evidence of marrow involvement in extramedullary acute myeloid leukaemia

Gastric myeloid sarcoma mimicking pseudoachalasia in non-leukemic context: a singular case report

Introduction and importance

Myeloid sarcoma (MS) is a rare tumour associated with acute myeloid leukaemia (AML) and occasionally occurs independently. It typically affects skin, bone, lymph nodes, and rarely the gastrointestinal tract, with gastric cases being extremely rare. Notably, no reported instances associate pseudoachalasia with gastric myeloid sarcoma.

Case presentation

A 20-year-old male presented with severe dysphagia, refractory vomiting, and weight loss. Diagnosed with type III achalasia via oesophageal tests, subsequent gastroscopy revealed a large gastric mass, later identified as gastric myeloid sarcoma through histopathology.

Clinical discussion

MS, characterized by immature blast cells, poses diagnostic challenges without typical leukaemia symptoms. Diagnosis involves immunohistochemistry, employing markers like CD33, CD34, and CD43. Optimal treatments, such as chemotherapy or stem cell transplantation, aim to delay leukaemia progression. Gastric primary de-novo myeloid sarcoma is exceedingly rare, emphasizing the need for tailored treatment strategies.

Conclusion

Gastric myeloid sarcoma is an exceptionally rare tumour, especially without concurrent acute myeloid leukaemia (AML), complicating its diagnosis. This case represents the first globally documented instance of gastric myeloid sarcoma causing pseudoachalasia. Documenting this unique clinical presentation is crucial for a better grasp of gastric myeloid sarcoma's diverse manifestations.

Isolated gastric myeloid sarcoma: a case report and review of the literature

Myeloid sarcoma represents the proliferation of myeloblasts of acute myeloid leukemia (AML) at extramedullary sites. While extramedullary involvement in AML is uncommon in itself, isolated myeloid sarcomas, that is, myeloid sarcomas without any bone marrow involvement, are extremely rare and pose a diagnostic and therapeutic challenge. Here, we present the case of a middle-aged woman with isolated myeloid sarcoma in the stomach-an organ seldom involved by this disease. Additionally, the literature on the epidemiology, diagnosis, pathology, prognosis, and therapeutic options in myeloid sarcomas has been reviewed.

Involvement of Gpr125 in the myeloid sarcoma formation induced by cooperating MLL/AF10(OM-LZ) and oncogenic KRAS in a mouse bone marrow transplantation model

Oncogenic N-/KRAS mutations were frequently associated with MLL/AF10 in acute myeloid leukemia with myeloid sarcoma (MS). To study the cooperating leukemogenesis by MLL/AF10 and KRAS mutation, we retrovirally transduced MLL/AF10(OM-LZ) and KRASG12C into mouse bone marrow cells and generated two immortalized cell lines. The cells carrying cooperating MLL/AF10(OM-LZ) and KRASG12C had immature myelomonocytic phenotypes. Compared to a previously established cell line carrying MLL/AF10(OM-LZ) alone, cooperation of MLL/AF10(OM-LZ) with KRASG12C blocked the cells at a more immature myelomonocytic stage with reduced expression of monocyte/macrophage markers. The mice transplanted with the cells carrying cooperating MLL/AF10(OM-LZ) and KRASG12C, liked those transplanted with the cells carrying MLL/AF10(OM-LZ) alone, induced myeloproliferative disease-like myeloid leukemia, but in a shorter latency and formed multiple MS at the adipose tissues of skin, peritoneum and intraperitoneal cavity. Cooperation of MLL/AF10(OM-LZ) with KRASG12C increased cell adhesion via upregulation of an adhesion G-protein-coupled receptor Gpr125. Knockdown of Gpr125 in the cells by short hairpin RNA reduced cell aggregation and diminished MS formation in the transplanted mice. Our results indicated that upregulation of Gpr125 by cooperating MLL/AF10(OM-LZ) and KRASG12C promoted cell adhesion and contributed to the MS formation.

Precursor B lymphoblastic leukemia 32 months after local therapy for a primary extramedullary myeloid cell tumor

A primary extramedullary myeloid cell tumor (pEMT) of an inguinal lymph node was completely excised without subsequent anti-tumor therapy in a 6-year-old child. Clinical observation and monitoring of blood and bone marrow (BM) did not reveal any pathologic results before 32 months, when a precursor B lymphoblastic leukemia was diagnosed. Identical T-cell receptor gamma rearrangement in nodal pEMT and in precursor B lymphoblastic leukemia in BM indicates a clonal relationship of these two tumors.

Karyotypic Identification of Abnormal Clones Preceding Morphological Changes or Occurring with No Definite Morphological Features of Myelodysplastic Syndrome: A Preliminary Study

The diagnosis of myelodysplastic syndrome (MDS) is difficult to establish based on morphologic features alone because dysplasia may not always be detectable and the presence of dysplasia is not itself evidence of clonal disorder. As a result, the detection of a clonal cytogenetic abnormality has a major role in difficult cases in regard to diagnosis and the recognition of morphological cytogenetic correlates. In an attempt to assess the frequency and characteristic type of abnormal clones when it is not clear whether or not a hematological condition is neoplastic, cytogenetics have been analyzed necessarily in 159 patients with unexplained cytopenia or suspected MDS. We found 14 patients (8.8%) with cytogenetic abnormalities in the absence of concomitant dysplastic features of the marrow at diagnosis. The cytogenetic changes were characteristic of those reported for myeloid malignancies: 3 del(20q), 2 Y chromosome losses, 2 del(5q), 2 11q23 abnormalities, and one each of t(3;5), i(7q), trisomy 8, and del(13q). One case of ring chromosome 4 was also found. A few months later, 3 of these patients showed marrow changes consistent with MDS. Our data demonstrated that a significant proportion of otherwise uncertain diagnoses presented abnormal clones. Long-term follow-up will be required to help determine the malignant potential of these clones.

Genomic profiling of myeloid sarcoma by array comparative genomic hybridization

Myeloid sarcoma (MS) is a tumor mass of myeloblasts or immature myeloid cells occurring in an extramedullary site. In this study, seven cases of MS [stomach (1), testis (1), skin (2), and lymph node (3)] and 3 synchronous and 1 follow-up bone marrow (BM) samples were studied for genomic abnormalities using array comparative genomic hybridization (array-CGH). Array-CGH construction used approximately 5,400 bacterial artificial chromosome clones from the RPCI-11 library, spanning the human genome. Data were analyzed using the DNAcopy software and custom heuristics. All MS cases had genomic abnormalities detected by array-CGH. Unbalanced genomic abnormalities in five MS cases were confirmed by conventional cytogenetics (CC) and/or fluorescence in situ hybridization (FISH); these abnormalities included loss of 4q32.1-q35.2, 6q16.1-q21, and 12p12.2-p13.2 and gain of 8q21.2-q24.3, 8, 11q21-q25, 13q21.32-q34, 19, and 21. Array-CGH was also invaluable in identifying possible deletions, partner translocations, and breakpoints that were questionable by CC. The remaining two MS cases had genomic aberrations detected by array-CGH, but were not studied further by CC/FISH. Chromosome 8 was most commonly abnormal (3/7 cases). Identical genomic abnormalities were demonstrated in MS and in synchronous BM in two cases. These results demonstrate that array-CGH is a powerful tool to screen MS tissue for unbalanced genomic abnormalities, allowing identification of chromosome abnormalities when concurrent BM is nonanalyzable or nonleukemic.

The Application of Molecular Analyses for Primary Granulocytic Sarcoma with a Specific Chromosomal Translocation

Primary granulocytic sarcoma (GS) is a rare disease defined by the absence of antecedent or concomitant leukemic cells in the bone marrow and the peripheral blood. Immunohistochemical staining for myeloperoxidase is necessary for a definite diagnosis. Otherwise, primary GS is often misdiagnosed as a malignant lymphoma or other malignancies. Primary GS is well known to frequently develop into acute myeloid leukemia (AML). Here we describe a 28-year-old woman with primary GS manifesting as an epidural tumor in the sacral region accompanied by meningeal dissemination. Fluorescence in situ hybridization analysis detected the AML1/MTG8 fusion gene in neoplastic cells obtained from her cerebrospinal fluid specimen and the epidural mass. The AML1/MTG8 fusion gene transcript was also detected by a nested reverse transcriptase-polymerase chain reaction analysis of mononuclear cells from the bone marrow, although leukemic cells were not recognized in a microscopical examination of the patient's bone marrow. Systemic chemotherapy with high-dose cytarabine followed by local radiotherapy was performed, and the patient clinically achieved a complete response. These molecular analyses provide a precise method of diagnosis, especially with respect to the French-American-British AML classification, according to the characteristic karyotypic alterations, and a patient consequently can quickly be given appropriate systemic chemotherapy as induction therapy.

Extramedullary acute myeloid leukemia (granulocytic sarcoma) with arm paresis, maculopapular exanthema and organ involvement

Granulocytic sarcoma (extramedullary myelosarcoma, chloroma) is a rare extramedullary myeloid tumor which can occur at any anatomical site as isolated finding or associated with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS). In this case, we describe a 71-year-old man who presented with incomplete paresis of the left arm, periorbital swelling, a maculopapular exanthema and organ involvement including testis and stomach. The tumors responded to combination chemotherapy and the patient fully recovered. However, after five months the patient relapsed and died quickly. This case confirms the importance of including granulocytic sarcoma in the differential diagnoses of a variety of diseases. In AML, the presence of granulocytic sarcoma is associated with worse overall survival. When diagnosed, it should be treated with intensive chemotherapy as soon as possible.

Cytogenetics, fluorescence in situ hybridization, and reverse transcriptase polymerase chain reaction are necessary to clarify the various mechanisms leading to an MLL-AF10 fusion in acute myelocytic leukemia with 10;11 rearrangement

In acute myelocytic leukemia (AML), predominantly in AML M5a, a recurrent chromosome aberration involves 11q23/MLL and the short arm of chromosome 10. Molecular studies have shown that the AF10 gene at 10p12 is consistently a partner gene in cases with 10;11 rearrangement. A simple reciprocal translocation cannot lead to the known MLL-AF10 fusion transcript because the 3' part of the MLL gene is orientated to the telomere and the 3' part of the AF10 gene to the centromere. In a series of 1897 AML samples, 14 cases (0.74%) showed 10;11 rearrangements leading to a MLL-AF10 fusion transcript. These cases were analyzed in detail with G banding analyses, fluorescence in situ hybridization, and molecular investigation in a single center. Five different mechanisms of (10;11) rearrangements leading to a MLL-AF10 fusion transcript can be observed (i.e., reciprocal translocations, insertions of either 10p into 11q or 11q into 10p, as well as complex and cryptic rearrangements). Compared to translocations involving MLL and other partner genes, complex rearrangements are unique for MLL-AF10 fusions. This may result from the opposite orientation of MLL and AF10.

Disseminated granulocytic sarcoma treated with allogeneic peripheral blood stem-cell transplantation

Primary granulocytic sarcoma is a rare disorder that presents as an extramedullary myeloid cell tumour. In this case, we describe a 35-year-old woman who developed widely disseminated granulocytic sarcomas three months after she received local radiotherapy to a primary granulocytic sarcoma of the cervical spine. These disseminated sarcomas initially responded to combination chemotherapy but this approach was only partly successful as the woman was left with increasing residual disease in the mediastinum. She was then treated with an allogeneic peripheral blood stem-cell transplant that led to complete resolution of her disease. This case demonstrates the effectiveness of allogeneic stem-cell transplantation in the treatment of progressive granulocytic sarcoma present after high-dose chemotherapy.

Isolated myelosarcoma in children--update and review

Primary myelosarcomas, also called leukemia cutis, granulocytic sarcomas or chloromas, are rare extramedullary manifestations of acute myeloid leukemia (AML) which precede bone marrow involvement. Skin infiltration was the most frequent localization associated with a myelomonocytic differentiation. Although first remission was achieved by most children, risk of relapse seemed to be increased. This might be caused by the specific biology of myelosarcomas, but also may be the result of delayed or reduced treatment. During the AML-BFM-studies 87/93/98 (11/1987-7/2000) 37 children with isolated myelosarcomas were diagnosed. Eighteen of the 37 patients survived with a 5-year overall survival estimation of 0.54+/-0.09 compared to 0.59+/-0.02; p(log rank) = 0.94. However, reduced or delayed treatment in 17 children led to an increased relapse rate of 71% compared to 35% in children treated soon after diagnosis. The 5-year overall survival in these patients was 0.41+/-0.11. According to our experience and review of the literature, an early diagnostic workup is needed in children with unusual skin lesions or tumors, considering myelosarcoma as primary manifestation of AML. Intensive AML-specific chemotherapy is generally recommended soon after diagnosis.

Overview. Cytogenetic analysis in haematology

Cytogenetic analysis has contributed greatly to our understanding of the nature of leukaemia and lymphoma. Study of these two groups of diseases has revealed general truths about the nature of the neoplastic process. Cytogenetic analysis has demonstrated that haematological neoplasms result from a somatic mutation occurring in a haemopoietic, lymphoid or multipotent stem cell. Complete remission has been related to disappearance of the clone of cells bearing the mutation whereas the occurrence of clonal evolution has often been found to be indicative of increasingly aggressive disease. Cytogenetic analysis of leukaemias and lymphomas has led to the discovery of numerous proto-oncogenes; these generally play a crucial role in proliferation and differentiation of normal cells with a perturbation of their function leading to neoplasia. In addition, cytogenetic evidence has suggested a role for loss of function of cancer-suppressing genes in haematological neoplasms. Cytogenetic analysis has also made major contributions to precise diagnosis and to the assigning of prognosis and, furthermore, by identifying good and poor prognostic groups has improved the management of patients. Good-prognosis patients have been spared unnecessary treatment and, conversely, more intensive treatment for some diseases associated with a cytogenetic abnormality that was previously indicative of a poor prognosis has improved the outcome for these patients.

Identification and molecular characterisation of a CALM-AF10 fusion in acute megakaryoblastic leukaemia

The t(10;11)(p13;q14-21) is a non-random translocation described in acute lymphoblastic and myeloid leukaemias. It results in the fusion of the gene CALM, which encodes a clathrin assembly protein, on 11q14 to the gene AF10, a putative transcription factor on 10p13. Here we describe for the first time, the occurrence of a CALM-AF10 fusion in a case of acute megakaryoblastic leukaemia. Fluorescence in situ hybridisation and reverse transcriptase polymerase chain reaction were used to confirm the presence of a CALM-AF10 fusion. A novel splice variant of CALM missing nt 1927-2091 was also detected. Though CALM is a cytoplasmic protein, the chimaeric fusion product is able to localise to both the nucleus and cytoplasm. Analysis of the fusion variants suggests, however, that the critical fusion product is likely to be cytoplasmic and contain the interactive leucine zipper of AF10.