Chronic myelomonocytic leukemia associated with myeloid sarcomas and NPM1 mutation: a case report and literature review

AML typical mutations (CEBPA, FLT3, NPM1) identify a high-risk chronic myelomonocytic leukemia independent of CPSS molecular

ABSTRACT

Mutations commonly associated with acute myeloid leukemia (AML), such as CEBPA, FLT3, IDH1/2, and NPM1, are rarely found in chronic myelomonocytic leukemia (CMML), and their prognostic significance in CMML has not been clearly identified. In 127 patients with CMML, we have retrospectively analyzed next-generation sequencing and polymerase chain reaction data from bone marrow samples collected at the time of CMML diagnosis. Seven patients harbored CEBPA mutations, 8 FLT3 mutations, 12 IDH1 mutations, 26 IDH2 mutations, and 11 NPM1 mutations. Patients with CMML harboring CEBPA, FLT3, and/or NPM1 mutations (mutCFN) more frequently had the myeloproliferative subtype, a high prevalence of severe cytopenia, and elevated blast counts. Regardless of their CMML Prognostic Scoring System molecular classification, mutCFN patients with CMML had a poor prognosis, and the multivariate analysis identified mutCFN as an independent marker of overall survival. The genetic profile of these mutCFN patients with CMML closely resembled that of patients with AML, with higher-risk clinical characteristics. Our findings lead us to suggest including the assessment of these mutations in CMML prognostic models and treating these patients with AML-type therapies, including intensive chemotherapy and allogeneic stem cell transplantation, whenever feasible. Furthermore, certain targeted therapies approved for use in AML should be considered.

Chronic myelomonocytic leukemia with NPM1 mutation or acute myeloid leukemia?

The 2022 WHO revision and the ICC classification have recently modified the diagnostic criteria for chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia. However, there is no consensus on whether CMML with NPM1 mutation (NPM1mut) should be diagnosed as AML. Nowadays, it is a subject of discussion because of its diagnostic and therapeutic implications. Therefore, we describe a case of a patient diagnosed with CMML NPM1mut and briefly review the literature to highlight the uncertainty about how to classify a CMML with NPM1 mutation. We emphasize the importance of a comprehensive molecular study, which is crucial to optimize the individualized treatment of patients, enabling them to access targeted therapies.

Infrequent Presentations of Chronic NPM1-Mutated Myeloid Neoplasms: Clinicopathological Features of Eight Cases from a Single Institution and Review of the Literature

Non-acute myeloid neoplasms (MNs) with NPM1 mutations (NPM1mut-MNs) pose a diagnostic and therapeutic dilemma, primarily manifesting as chronic myelomonocytic leukemia (CMML) and myelodysplastic syndromes (MDS). The classification and treatment approach for these conditions as acute myeloid leukemia (AML) are debated. We describe eight cases of atypical NPM1mut-MNs from our institution and review the literature. We include a rare case of concurrent prostate carcinoma and MN consistent with chronic eosinophilic leukemia, progressing to myeloid sarcoma of the skin. Of the remaining seven cases, five were CMML and two were MDS. NPM1 mutations occur in 3-5% of CMML and 1-6% of MDS, with an increased likelihood of rapid evolution to AML. Their influence on disease progression varies, and their prognostic significance in non-acute MNs is less established than in AML. Non-acute MNs with NPM1 mutations may display an aggressive clinical course, emphasizing the need for a comprehensive diagnosis integrating clinical and biological data. Tailoring patient management on an individualized basis, favoring intensive treatment aligned with AML protocols, is crucial, regardless of blast percentage. Research on the impact of NPM1 mutations in non-acute myeloid neoplasms is ongoing, requiring challenging prospective studies with substantial patient cohorts and extended follow-up periods for validation.

Nucleophosmin1 (NPM1) abnormality in hematologic malignancies, and therapeutic targeting of mutant NPM1 in acute myeloid leukemia

Nucleophosmin (NPM1) is an abundant nucleolar protein that is implicated in a variety of biological processes and in the pathogenesis of several human malignancies. For hematologic malignancies, approximately one-third of anaplastic large-cell non-Hodgkin’s lymphomas were found to express a fusion between NPM1 and the catalytic domain of anaplastic lymphoma receptor tyrosine kinase. About 50–60% of acute myeloid leukemia patients with normal karyotype carry NPM1 mutations, which are characterized by cytoplasmic dislocation of the NPM1 protein. Nevertheless, NPM1 is overexpressed in various hematologic and solid tumor malignancies. NPM1 overexpression is considered a prognostic marker of recurrence and progression of cancer. Thus, NPM1 abnormalities play a critical role in several types of hematologic malignancies. This has led to intense interest in the development of an NPM1 targeting strategy for cancer therapy. The aim of this review is to summarize present knowledge on NPM1 origin, pathogenesis, and therapeutic interventions in hematologic malignancies.

Urgent Chemotherapy Successfully Rescues a Near Death Patient of Acute Intracranial Hypertension Caused by Intracranial Myeloid Sarcoma

Intracranial myeloid sarcoma is a very rare disease with poor prognosis. We report a case of a 28-year-old male patient who was admitted with intense headache, vision disturbance and severe vomiting in June 2017. He had a history of neurosurgical tumor resection operation in April 2017, and the pathological diagnosis was intracranial myeloid sarcoma. Bone marrow aspirate and biopsy had been conducted in May 2017, which demonstrated 5.5% blasts expressing CD13, CD33, CD34, CD117 and MPO, and the cytogenetic analysis demonstrated t(8;21)(q22;q22), and molecular studies showed a positive RUNX1-RUNX1T1 rearrangement. The diagnosis of acute myeloid leukemia (AML) with t (8; 21) (q22; q22)/RUNX1-RUNX1T1 was made, however, the patient refused to receive any systemic chemotherapy. Emergency cranial CT demonstrated a circular hyperdense mass (54mm×37mm), which was surrounded by hypodense peritumoral edema in the left cerebellar hemisphere, and the density of the lesions was uniform and the margin was clear. Idarubicin (12mg/m²·d×3 days) combined with high-dose cytarabine (2g/m² q12h×3 days) was initiated for emergency chemotherapy. All of the above symptoms disappeared at the end of chemotherapy. On the first day after chemotherapy, the cranial CT indicated that the cranial lesion was markedly reduced (20mm×15mm), and on the sixth day after chemotherapy, the lesion was completely disappeared. Currently, there are no clear guidelines for the treatment of intracranial myeloid sarcoma, and our treatment approaches could provide a reference for this disease with such emergency situation.