No abstract available.
Myeloid Cells*

Chloroma is an invasive extramedullary tumor composed of immature myeloid cells, which complicates the clinical course in a minority of patients with acute myeloid leukemia (AML). The presence of myeloid sarcoma is known to be a poor prognostic indicator in patients with AML. However, the optimal treatment of AML with concurrent chloroma has not been determined. We report four patients with AML accompanied by concurrent chloroma from the time of initial diagnosis. All of the patients underwent hematopoietic stem cell transplantation after complete remission. We also present a review of the literature.
Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; Humans ; Leukemia, Myeloid, Acute ; Myeloid Cells ; Sarcoma, Myeloid

CD137 (4-1BB/tnfrsf9) has been shown to co-stimulate T cells. However, agonistic anti-CD137 monoclonal antibody (mAb) treatment can suppress CD4+ T cells, ameliorating autoimmune diseases, whereas it induces activation of CD8+ T cells, resulting in diverse therapeutic activity in cancer, viral infection. To investigate the CD137-mediated T cell suppression mechanism, we examined whether anti-CD137 mAb treatment could affect CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs). Intriguingly, anti-CD137 mAb injection significantly increased CD11b+Gr-1+ cells, peaking at days 5 to 10 and continuing for at least 25 days. Furthermore, this cell population could suppress both CD8+ T cells and CD4+ T cells. Thus, this study demonstrated that, for the first time, anti-CD137 mAb treatment could induce CD11b+Gr-1+ MDSCs under normal conditions, suggesting a possible relationship between myeloid cell induction and CD137-mediated immune suppression.
Autoimmune Diseases ; Immunosuppression ; Myeloid Cells ; T-Lymphocytes

In recent years, studying the role of myeloid-derived suppressor cells (MDSCs) in many pathological inflammatory conditions has become a very active research area. Although the role of MDSCs in cancer is relatively well established, their role in non-cancerous pathological conditions remains in its infancy resulting in much confusion. Our objectives in this review are to address some recent advances in MDSC research in order to minimize such confusion and to provide an insight into their function in the context of other diseases. The following topics will be specifically focused upon: (1) definition and characterization of MDSCs; (2) whether all MDSC populations consist of immature cells; (3) technical issues in MDSC isolation, estimation and characterization; (4) the origin of MDSCs and their anatomical distribution in health and disease; (5) mediators of MDSC expansion and accumulation; (6) factors that determine the expansion of one MDSC population over the other; (7) the Yin and Yang roles of MDSCs. Moreover, the functions of MDSCs will be addressed throughout the text.
Biology ; Humans ; Myeloid-Derived Suppressor Cells ; Neoplasms

Myeloid sarcoma is a solid, extramedullary tumor composed of leukemic myeloblasts or immature myeloid cells. Intraparenchymal myeloid sarcoma without the involvement of the skull or meninges is extremely rare. Here, we present the case of a 49-year-old man who developed intraparenchymal myeloid sarcoma on the left cerebellum after allogeneic bone marrow transplantation (BMT). He received radiotherapy after complete removal of intraparenchymal myeloid sarcoma, but he was diagnosed spinal myeloid sarcoma three month later. Nine months after the operation, new intracranial and spinal myeloid sarcoma were diagnosed and the patient's condition had been worsened rapidly. Although the spinal myeloid sarcoma was not histologically diagnosed, this report provides valuable insights into the clinical course of progression of intraparenchymal myeloid sarcoma.
Bone Marrow Transplantation ; Cerebellum ; Granulocyte Precursor Cells ; Humans ; Leukemia, Myeloid, Acute ; Meninges ; Middle Aged ; Myeloid Cells ; Sarcoma, Myeloid ; Skull

Multiple myeloma (MM) is characterized by a population of functionally heterogeneous cells, in which identifying the target cells causing molecular lesion is a fundamental issue. The resultant tumor stem/progenitor cells comprise only a minor portion of the myeloma cells, which give rise through differentiation to more committed progenitors as well as differentiated blasts that constitute the bulk of the tumor. Although they are rare as compared with fully differentiated plasma cells, MM stem/progenitor cells are likely responsible for the maintenance and progression of disease through the production of new tumor cells. Thus, this is the cell population which must be eradicated for successful treatment. This article reviewed apparently conflicting evidence pertaining to the cellular origins of MM and proposed that myeloma may originate in more cellular components. In this article, the nature of the target cells, the identification and phenotypic analyses of clonogenic myeloma cells, the signaling pathways within myeloma stem/progenitor cells and the target therapy related were reviewed as well.
Humans ; Multiple Myeloma ; therapy ; Myeloid Progenitor Cells ; Neoplastic Stem Cells

Myeloid sarcoma is an uncommon extramedullary tumor of immature myeloid cells or myeloblasts. It may occur alone or concurrently with an underlying hematological malignancy. Although it can develop anywhere in the body, common sites include bones, particularly the skull and vertebra, soft tissues, and lymph nodes. However, there have been few reports of myeloid sarcoma occurring in the respiratory system, especially the large airways. We describe a case of endobronchial relapse of acute myeloid leukemia in a patient who achieved complete remission after allogeneic stem cell transplantation. To our knowledge, this is the first such report in Korea.
Granulocyte Precursor Cells ; Hematologic Neoplasms ; Humans ; Korea ; Leukemia, Myeloid, Acute ; Lymph Nodes ; Myeloid Cells ; Recurrence ; Respiratory System ; Sarcoma, Myeloid ; Skull ; Spine ; Stem Cell Transplantation ; Stem Cells

Myeloid sarcoma is a rare condition that's caused by the aggregation of immature myeloid cells in leukemic patients. Myeloid sarcoma occurring in the temporal bone more frequently involves the mastoid bone than is the case for metastatic lesions arising from non-systemic malignancies. The disease is difficult to diagnose when it presents with symptoms that mimic otomastoiditis. However, an early diagnosis is important in order to achieve complete remission of the disease. Magnetic resonance imaging of the temporal bone is useful for making the diagnosis of myeloid sarcoma, and especially to evaluate the extent of disease. High-dose radio- or chemotherapies are the first-line approaches and possibly the only approaches to achieve complete remission and to cure the disease. With the aim of improving our understanding of myeloid sarcoma in the temporal bone, the present report describes our experience with 5 such cases and we compare the clinical features of these 5 patients with those clinical features of patients who have metastatic lesions.
Early Diagnosis ; Humans ; Hydrazines ; Magnetic Resonance Imaging ; Mastoid ; Myeloid Cells ; Sarcoma, Myeloid ; Temporal Bone

Granulocytic sarcoma, also called chloroma or myeloblastoma, is an extramedullary invasive tumor composed of neoplastic myeloid cells. In this report, we describe a 43-year-old male patient with a collision tumor composed of an adenocarcinoma and a granulocytic sarcoma in the stomach. The coexistence of a granulocytic sarcoma and adenocarcinoma in the stomach has, to the best of our knowledge, not been reported in the literature. The diagnosis of granulocytic sarcoma is very difficult; especially in the absence of concurrent hematologic disease or in the uncommon setting of coexistence with another tumor. Cautious observation is needed when a finding of unusual atypical cells admixed with an adenocarcinoma in the stomach is confronted.
Adenocarcinoma ; Adult ; Hematologic Diseases ; Humans ; Male ; Myeloid Cells ; Sarcoma, Myeloid ; Stomach

Granulocytic sarcoma is an extramedullary tumor composed of granulocytic precursor cells. It usually presents as a nodular mass in the course of acute myelogenous leukemia. Rarely, the tumor develops in non-hematological conditions or in a patient with complete remission from the acute myelogenous leukemia. In such cases, aleukemic granulocytic sarcoma can be a preceding sign of systemic leukemia or a first sign of hematologic relapse of leukemia. We present an unusual case of multiple granulocytic sarcomas developed in a patient with longstanding complete remission of acute myelogenous leukemia, who has not had bone marrow and peripheral blood involvement for a long time.
Bone Marrow ; Granulocyte Precursor Cells ; Humans ; Leukemia ; Leukemia, Myeloid, Acute ; Recurrence ; Sarcoma, Myeloid