Myeloid Neoplasia and Other Leukemias No abstract available

Unusual Presentation of Myeloid Sarcoma in a Patient With Usher Syndrome A 45-year-old woman with Usher syndrome, associated congenital deafness, progressive blindness due to retinitis pigmentosa, and latent autoimmune diabetes presented to the emergency department with malaise, dizziness, and pelvic pain following removal of an intrauterine device. A posterior vaginal wall mass was found on examination. Laboratory values demonstrated anemia, thrombocytopenia, and an elevated white blood cell count, raising concern for infection and potential onset of diabetic ketoacidosis. This prompted a peripheral blood smear review, which showed 60% monocytic blasts. A subsequent vaginal mass biopsy showed a myeloid sarcoma. Molecular studies demonstrated an NPM1 mutation in exon 12 without FLT3 mutation or internal tandem duplication. While a diagnosis of acute myeloid leukemia with mutated NPM1 was considered, cytogenetics revealed a complex karyotype with evidence of clonal evolution, consistent with acute myeloid leukemia with myelodysplasia-related changes. In addition to an unusual presentation of myeloid sarcoma, this case posed significant questions regarding management and pursuit of hematopoietic stem cell transplantation. Usher syndrome is genetically and clinically heterogeneous. While it is not known to be associated with increased risk of malignancy, mutation of genes associated with Usher syndrome has been identified in acute leukemia. Our case raises the question as to whether potential germline predisposition should be considered in a patient with a previously unassociated congenital syndrome.

Chronic Myelomonocytic Leukemia in a Patient With a Germline Predisposition and Short Telomeres Myeloid neoplasms with germline predisposition are an increasingly recognized category within the World Health Organization classification. Detection requires a high degree of suspicion, with mounting awareness of clinically silent phenotypes and heterogeneous presentations, challenging diagnostic and laboratory testing considerations, need for surveillance of disease progression, and unique concerns in donor selection for stem cell transplantation. We describe the case of a patient who presented as a teenager with thrombocytopenia and was later diagnosed with chronic myelomonocytic leukemia, with eventual transformation to acute myeloid leukemia, which has relapsed after stem cell transplantation. She was found to have short telomeres and a TERT mutation, in addition to numerous features suggestive of a germline predisposition syndrome. These findings have not been specifically associated with chronic myelomonocytic leukemia and raise interesting questions about the associations between myelodysplastic/myeloproliferative neoplasms, telomere biology disorders, and the roles of specific myeloid mutations as drivers of disease.

Next-Generation Sequencing Analysis in Posttransplant Relapsed Acute Myeloid Leukemia Reveals Clonal Evolution and Donor-Derived Germline Variant Indicating Bone Marrow Chimerism The era of next-generation sequencing (NGS) has led to a deeper understanding of the genetic complexity and heterogeneity of this disease, in addition to revealing mechanisms of disease relapse. Clinical NGS is becoming routine in clinical practice in both solid organ and hematologic malignancies to identify molecular markers of disease that might assist with diagnosis, prognosis, and the treatment of cancer. These tumor-specific markers also enable treatment response monitoring, as they serve as clonal markers unique to the disease. Continuous molecular monitoring also allows identification of disease recurrence with potentially new actionable mutations. This practice is complicated in the setting of allogeneic bone marrow transplant, as the admixtures of donor and recipient DNA pose unique challenges to NGS interpretation. This case highlights the importance of systematic methodological interpretation of NGS results to better understand the clinical significance and impact of new mutations discovered posttransplant and reveals another potential application of NGS for bone marrow engraftment analysis.

Unclassifiable Myelodysplastic/Myeloproliferative Neoplasm With Hypocellularity: A Classification Conundrum Myelodysplastic/myeloproliferative neoplasm (MPN), unclassifiable (MDS/MPN-U), has clinical and morphologic features of both myelodysplastic syndrome (MDS) and myeloproliferative neoplasms (MPNs), and does not meet diagnostic criteria for any other specific entity within MDS, MPN, or MPN, including therapy-related myeloid neoplasms, and cases evolving from a prior MDS or MPN. Diagnostic criteria for MDS/MPN-U include, among other specifications, a platelet count of greater than or equal to 450 × 10E9/L associated with bone marrow megakaryocytic proliferation. We present the case of a young adult patient with a several-year reported history of cytopenias, found to have thrombocytosis and 5% circulating blasts. Surprisingly, his bone marrow biopsy demonstrated hypocellularity (10%), with 5% to 10% blasts, myeloid hypoplasia, minimal fibrosis, and focal megakaryocytic dyspoiesis but no hyperplasia. The constellation of morphologic and clinical features presents a challenging differential diagnosis between MDS/MPN-U and MDS with excess blasts (as well as thrombocytosis). Molecular testing interestingly demonstrated an SF3B1 mutation, although no increased ring sideroblasts were found by iron staining. Cases such as these may prove instructive in refining our understanding of the MDS/MPN category, as well as its relationship to myelodysplasia and the complex molecular genetic landscape underlying myeloid neoplasia.

Granulomatous Slack Skin T-Cell Lymphoma Manifesting as Ulcerative and Gangrenous Lesions With a Fatal Outcome: A Case Report and Review of the Literature Granulomatous slack skin is an extremely rare cutaneous T-cell lymphoma, which often pursues an indolent disease course. Clinically, it is characterized by areas of redundant and lax skin in flexural areas, with variable erythema. Histologic findings include granulomatous T-cell infiltrates with loss of elastic fibers and poikilodermic change. In this article, we report a patient with unusual rapidly progressive ulcerative and gangrenous skin lesions, leading to amputation and ultimately demise. We also review the literature on granulomatous slack skin with similarly aggressive clinical course and discuss the differential diagnosis.

MYC Alteration by Chromothripsis Event in Aggressive High-Grade B-Cell Lymphoma Negative by Conventional Fluorescence In Situ Hybridization Analysis: A Case Report Double-hit and double-expressor phenotypes in lymphomas are characterized by activation of the expression of the MYC and BCL2 genes through diverse mechanisms including chromosomal translocations and amplifications. Herein, we report a high-grade B-cell lymphoma in a patient with evidence for a chromothripsis event (via chromosomal microarray methodology) at chromosome 8, resulting in a focal copy number gain of the MYC locus, not detected by conventional fluorescence in situ hybridization for MYC despite strong MYC expression by immunohistochemical analysis. Chromosome analysis from the biopsy was not successful because of an extensive tissue necrosis. Chromothripsis is suggested as another mechanism for the activation of MYC in non-Hodgkin lymphoma, resulting in aggressive disease course, and this case underscores the need for chromosomal microarray testing in select cases to identify aggressive biology.

Unusual Cases of Hairy Cell Leukemia With Uncommon Immunophenotypes: A Diagnostic Challenge Hairy cell leukemia (HCL) is a rare indolent B-cell neoplasm with distinct morphologic and immunophenotypic features. Immunophenotypically, the neoplastic cells in HCL are strongly positive for B-cell markers, such as CD19, CD20, and CD22. They also characteristically express CD11c, CD25, CD103, and CD123, but lack CD5, CD10, and CD23. Uncommon immunophenotypes of HCL can pose diagnostic challenges. Here, we report 2 unusual cases of CD5-positive and CD10-positive HCL.

Hairy Cell Leukemia Presenting as Presternal Soft Tissue Mass: A Case Report With Review of Literature Hairy cell leukemia (HCL) is an uncommon chronic lymphoproliferative disorder. Initial presentation frequently includes symptoms related to peripheral blood cytopenias. It can sometimes have atypical manifestations and can present at unusual sites. We report an unusual presentation of HCL as a presternal soft tissue mass in a 45-year-old man. His peripheral blood counts showed pancytopenia. There were no palpable lymph nodes or hepatosplenomegaly. CT-scan revealed a middle mediastinal mass with extension into the presternal soft tissue. Tissue core biopsy was taken and histopathologic findings confirmed the diagnosis of HCL. To our knowledge, this is the second reported case of HCL presenting as a presternal soft tissue mass. Although rare, HCL should be considered in the differential diagnosis of tumors involving extramedullary/extranodal sites including the soft tissue and bone, so the patient can get the utmost benefit for early diagnosis of a treatment responsive disease.

Myeloid Sarcoma of the Urinary Bladder Associated With t(8;21): Case Report and Review of the Literature Myeloid sarcoma is a malignant neoplasm of myeloid lineage that occurs in extramedullary sites, frequently in patients with acute myeloid leukemia and other myeloproliferative and myelodysplastic syndromes. Myeloid sarcoma of the urinary bladder is exceptionally rare, and although the most common cytogenetic abnormality associated with this lesion is t(8;21)/RUNX-RUNX1T1, to the best of our knowledge, there are no previous reports of this in patients with bladder involvement. We report a case of a 30-year-old man with a urinary bladder mass, which was consistent with myeloid sarcoma with t(8;21). The importance of myeloid sarcoma of the bladder is that it could be misdiagnosed and must be differentiated from other poorly differentiated bladder tumors composed of round cells, mainly because it is a malignant neoplasm with a good response to treatment, which does not require surgery.