Leukemic stem cells and advances in hematopoietic stem cell transplantation for acute myeloid leukemia: a narrative review of clinical trials.

Objective: The purpose of this literature review is to summarize and provide a brief overview of our current understanding of acute myeloid leukemia (AML) and the role of stem cell transplantation (SCT) in its management. Background: AML is a malignant hematological disorder that is characterized by the uncontrolled proliferation of myeloid blood cells. This disease has been associated with various risk factors such as ionizing radiation, cigarette smoke, pesticides/herbicides, and chemotherapy. SCT remains the most beneficial treatment for medically fit AML patients due to superior survival outcomes. Methods: A thorough search was conducted on PubMed, Scopus, ClinicalTrials.gov, Embase and Web of Science using related keywords. Current articles on the uses of stem cell therapy in AML patients were selected. Conclusions: Long term exposure to ionizing radiation and other harmful substances such as benzene, cigarette smoke and chemotherapeutic drugs plays an important role in AML carcinogenesis. Mutations in certain genes (e.g., ASXL1, RUNX1, KIT, TP53, BCR-ABL1) seem to accelerate the process as they affect normal cellular proliferation and cell death. These events may give rise to a small subpopulation of leukemic stem cells (LSC) which continuously sustain tumor development and growth. Patients who are deemed to be medically "fit" should receive an allogenic hematopoietic stem cell transplantation (allo-HSCT) due to improved overall survival (OS) (~50%) and decreased relapsed risk (32% vs. 59%). Several studies have revealed that the medically "unfit" may benefit from more conventional agents such as azacytidine, decitabine, venetoclax or sorafenib.

An Unusual Case of Severe Cystic Lung Disease: A Case Report and Review of the Literature.

Cystic lung diseases are a heterogeneous group of disorders with varying presentations and pathophysiology. They present as air-filled lung cysts that are prone to rupture and result in spontaneous pneumothoraxes. While pulmonary cysts are not uncommon, cysts presenting later in life with unclear etiology are rare and result in both a diagnostic and therapeutic challenge. In this report, we present a case of an 82-year-old female presenting with shortness of breath and hemoptysis. Computed tomography (CT) angiogram showed multiple pulmonary cysts with one of the cysts containing an air-fluid level suspicious of superimposed infection. Pulmonary cysts are characteristic of different diseases that include but are not limited to Langerhans cell histiocytosis (LCH), lymphangioleiomyomatosis (LAM), and Birt-Hogg-Dube (BHD) syndrome. The differential diagnosis of cystic lung disease over the years has become more complex. Clinical context and radiological findings are essential for diagnosis.