Minimally differentiated acute myeloid leukemia (AML-M0) with extensive erythrophagocytosis and del(20)(q11) chromosome abnormality

A Case Report and Review of B‑Lineage Acute Lymphoblastic Leukemias with Cannibalistic Lymphoblasts: A Unique Morphologic and Molecular Genetic Entity?

Cannibalism is a type of “cell-in-cell” phenomenon commonly described in myeloid lineage malignancies. Although lymphocytes and their precursors are inherently non-phagocytic, there are sporadic case reports describing cannibalism by leukemic lymphoblasts. In the current manuscript, we report the case of a pediatric B-lineage acute lymphoblastic leukemia (B-ALL) patient showing cannibalistic lymphoblasts and have reviewed the clinical and laboratory characteristics of similar cases documented in literature. Our manuscript highlights that all reported B-ALL patients showing cannibalistic lymphoblasts had intra-cytoplasmic vacuolations, and all such treatment-naïve pediatric patients were ETV6-RUNX1 fusion positive and had aberrant expression of myeloid lineage antigens.

Erythrophagocytosis by leukemic blasts in acute myeloid leukemia with a normal karyotype and no detectable mutations

The phagocytosis of erythrocytes by leukemic blasts is a rare finding in acute myeloid leukemia and has been reported most commonly in monocytic and megakaryocytic morphologies. In the reported cases, erythrophagocytosis by leukemic blasts has been associated with t(8;16). This translocation is associated with a poor outcome independent of erythrophagocytosis. There has only been one reported case of erythrophagocytosis by leukemic blasts occurring in a patient with a normal karyotype. We report a 62-year-old woman with acute myeloid leukemia with monocytic features and a normal karyotype noted to have erythrophagocytosis by leukemic blasts.

Erythrophagocytosis by blasts in a case of de novo acute monoblastic leukemia with rare but characteristic t(8;16)

Erythrophagocytosis by leukemic blasts is a rare phenomenon. We report a case of a female diagnosed with acute monoblastic leukemia with leukemic blasts that were CD34 and CD117 negative, showing erythrophagocytosis, vacoulations, and a rare t(8;16) on bone marrow karyotype which is associated with a poor prognosis despite intensive chemotherapy. Meticulous bone marrow examination in such a scenario may point towards the presence of t(8;16) and help clinicians take a well-informed clinical decision.

Normal karyotype in a case of acute myeloid leukemia with monocytic differentiation and hemophagocytosis by leukemic blasts

We report the case of a 39-year-old woman with acute myeloid leukemia (AML) with monocytic differentiation showing hemophagocytosis by leukemic blasts. This phenomenon is known to be associated with certain chromosomal changes, including t(8;16), der(8), inv(8), and t(16;21); however, in this case, the patient had a normal female karyotype. To our knowledge, this is the first published case of normal karyotype AML with hemophagocytosis by leukemic blasts.

Secondary Philadelphia chromosome and erythrophagocytosis in a relapsed acute myeloid leukemia after hematopoietic cell transplantation

The acquisition of the Philadelphia chromosome (Ph) as a secondary change during the course of hematopoietic malignancies is rare and is associated with poor prognosis. Few cases of secondary Ph have been reported after hematopoietic cell transplantation (HCT). A secondary Ph at relapse is of clinical importance because it provides a therapeutic target for tyrosine kinase inhibitors along with or in replacement of chemotherapy. We describe a case of relapsed acute myeloid leukemia (AML) after HCT that developed a BCR-ABL1 translocation along with erythrophagocytosis by blasts as a secondary change at the time of relapse. The progression of this patient's myeloid neoplasm from myelodysplastic syndrome to AML to relapsed AML after HCT was accompanied by a stepwise cytogenetic evolution: A deletion 20q abnormality subsequently acquired a deletion 7q and, finally, at relapse after HCT, a secondary Ph was gained. The relationship between the secondary Ph and the erythrophagocytosis by blasts is not clear. We review the possible pathogenesis and cytogenetic associations of erythrophagocytosis by blasts, a rare feature in acute leukemias.

Morphology, cytogenetics, and survival in myelodysplasia with del(20q) or ider(20q): a multicenter study

Isochromosome of the long arm of chromosome 20 with interstitial loss of material [ider(20q)] is a rare cytogenetic abnormality reported in myelodysplastic syndrome (MDS), with neither specific morphological pattern nor clear prognostic significance. The aim of this retrospective multicentric study is to compare the peripheral blood and bone marrow morphology of MDS patients with ider(20q) (n = 13) and del(20q) (n = 21) and controls (n = 47) in order to investigate whether the ider(20q) harbors specific morphological features. The secondary objective is to compare the outcome of patients from both groups. This study performed on the largest cohort of MDS patients with ider(20q) is the first that identifies specific morphological features (hypogranulated and vacuolized neutrophils and neutrophil erythrophagocytosis) allowing the identification of this cytogenetic abnormality with high sensitivity (70%) and specificity (85.7%). Suspected ider(20q) by morphology should therefore support targeted FISH tests in case of non informative karyotype. This combined approach will allow a better estimation of the prevalence of this underdiagnozed entity. The overall survival and progression-free survival did not statistically differ in both groups. However, hypogranulated and vacuolized neutrophils were significantly associated with survival.

Pseudo-Gaucher cell proliferation associated with myelodysplastic syndrome

We report an extremely rare case of pseudo-Gaucher cell proliferation with myelodysplastic syndrome (MDS). A 77-year old Japanese man was referred to our hospital with splenomegaly and thrombocytopenia, and subsequent bone marrow aspiration revealed infiltrates of foamy vacuolated macrophages without any evidence of other morphologic abnormalities. A karyotype analysis showed the presence of 46,XY,del(20)(q11) in 20 of 20 examined bone marrow cells. We performed a splenectomy, and the resulting pathologic findings revealed massive infiltration of foamy vacuolated macrophages, which were morphologically compatible with Gaucher cells. The activities of beta-glucosidase and acid sphingomyelinase were within normal ranges; therefore, the foamy vacuolated macrophages were considered pseudo-Gaucher cells. A diagnosis of MDS, subclassified as refractory anemia, was then made according to World Health Organization classification guidelines. Pseudo-Gaucher cell proliferation and infiltration might therefore be observed in other patients presenting with MDS.

Erythrophagocytosis by dysplastic neutrophils in chronic myelomonocytic leukemia and subsequent transformation to acute myeloid leukemia

Erythrophagocytosis by neutrophils is a rare phenomenon in myeloid malignancies, and its clinicopathologic significance is not fully understood. We report a unique case of erythrophagocytosis by dysplastic neutrophils in chronic myelomonocytic leukemia (CMML) and subsequent transformation to acute myeloid leukemia (AML). Review of multiple marrow samples, both pretreatment and post-treatment, demonstrated a correlation between percentage of dysplastic neutrophils and degree of erythrophagocytosis. Erythrophagocytosis was observed only in dysplastic forms of neutrophils. Post-transplant marrows with engraftment of donor cells showed no neutrophilic dysplasia or erythrophagocytosis. Possible mechanisms of neutrophilic erythrophagocytosis in myeloid malignancies are discussed.

Hemophagocytosis exacerbated by G-CSF/GM-CSF treatment in a patient with myelodysplasia

We describe a 75-year-old man with neutropenia in whom bone marrow aspirate and biopsy demonstrated hemophagocytosis associated with myelodysplasia (MDS). Therapy with granulocyte-colony stimulating factor (G-CSF) and granulocyte-monocyte-colony stimulating factor (GM-CSF) caused splenomegaly and severe thrombocytopenia, which recurred upon rechallenge. We propose that myeloid growth factors may be detrimental in patients with MDS-associated hemophagocytosis.

Acute myeloid leukaemia M0: haematological, immunophenotypic and cytogenetic characteristics and their prognostic significance: an analysis in 241 patients

Haematological, immunophenotypic and cytogenetic characteristics were analysed in 241 patients with acute myeloid leukaemia (AML) M0, including 58 children. Children < 3 years and adults between 60 and 70 years of age were most frequently affected. Immunophenotyping showed a heterogeneous phenotype. Anti-myeloperoxidase was positive in about half of the patients. Cytogenetic data were available from 129 (54%) patients. A normal karyotype was found in only 24%. Most of the abnormalities were unbalanced and the chromosomes 5, 7, 8 and 11 were the most frequently affected. Survival data were available from 152 treated patients (63%). The median overall survival for all patients was 10 months, 20 months for children (n = 36), 10 months for the young adult group (n = 50) and 7 months for the elderly patients (n = 66) (P = 0.09). Karyotype was not a prognostic factor influencing survival. AML M0 shows the immunological characteristics of early progenitor cells, but the expression of the different markers and cytogenetic abnormalities is heterogeneous. The prognosis is poor compared with other de novo AML and similar to that of AML with multilineage dysplasia or AML following myelodysplastic syndromes.