Acute myelomonocytic leukemia with multifocal manifestation and spinal cord infiltration in a dog.

INTRODUCTION: Few cases of myelomonocytic leukemia associated with neurological signs have been described in dogs; none have been related to intraparenchymal spinal cord infiltration by neoplastic cells. This short communication describes a case of acute myelomonocytic leukemia subtype M4 in a dog with spinal cord infiltration. A 3-year-old male Golden Retriever was presented with a history of hyperthermia, lymphadenomegaly, leukocytosis with circulating blast cells, anemia and thrombocytopenia, and acute onset paraplegia. Immunophenotyping of peripheral blood by flow cytometry was consistent with acute myelomonocytic leukemia subtype M4. The dog was euthanized because of clinical deterioration and unfavourable prognosis. Postmortem examination revealed multi-organ neoplastic infiltration, including the spinal cord. To our knowledge, this is the first case of acute myelomonocytic leukemia subtype M4 in a dog with spinal cord infiltration. Our findings hold importance for including myelomonocytic leukemia in the differential diagnosis of patients with neurological signs due to spinal cord localisation.

INTRODUCTION: Peu de cas de leucémie myélomonocytaire associés à des signes neurologiques ont été décrits chez le chien ; aucun n'était lié à une infiltration intraparenchymateuse de la moelle épinière par des cellules néoplasiques. Cette courte communication décrit un cas de leucémie aiguë myélomonocytaire de sous-type M4 chez un chien avec infiltration de la moelle épinière. Un Golden Retriever mâle de 3 ans a été présenté avec une anamnèse d'hyperthermie, de lymphadénomégalie, de leucocytose avec des cellules blastiques circulantes, d'anémie et de thrombocytopénie et de paraplégie d'apparition aiguë. L'immunophénotypage du sang périphérique par cytométrie de flux était compatible avec une leucémie myélomonocytaire aiguë de sous-type M4. Le chien a été euthanasié en raison de la détérioration de son état clinique et du pronostic défavorable. L'examen post-mortem a révélé une infiltration néoplasique multi-organique, y compris la moelle épinière. À notre connaissance, il s'agit du premier cas de leucémie aiguë myélomonocytaire de sous-type M4 chez un chien avec infiltration de la moelle épinière. Nos résultats sont importants pour inclure la leucémie myélomonocytaire dans le diagnostic différentiel chez les patients présentant des signes neurologiques dus à une localisation médullaire.

Pure erythroid leukemia subsequent to acute myelomonocytic leukemia: A case report.

RATIONALE: Pure erythroid leukemia is a rare subcategory of acute myeloid leukemia characterized by predominant immature erythroid population. Its occurrence subsequent to acute myelomonocytic leukemia has not been reported before. We reported this rare case to call attention because it may pose a diagnostic challenge. PATIENTS CONCERNS: A 54-year-old female patient presented to our hospital in March 2018 with symptoms of easy fatigability. DIAGNOSIS: Bone marrow aspiration was hypercellular showing 67.2% blasts mainly including moderate myeloblasts and monoblasts. There was mild dysplasia with some cells having round, oval, or bizarre nuclei which containing 1 to 3 nucleolus. Erythroid lineage was hypoplasia and mature erythrocytes were generally normal. Conventional cytogenetics of bone marrow cells revealed complex karyotype (44, XX, del (5) (q14q34) del (5) (q14q34), del (14) t (11;14) (q10; q10), -16, del (17), -18[10]). INTERVENTIONS: The patient was treated with second line chemotherapy but did not respond. QUTCOMES: She died of cardiopulmonary failure 19days after starting of therapy. LESSONS: This unexpected and relatively uncommon occurrence was associated with a universally rapid and fatal clinical course with survival measured in <2 months despite intensive chemotherapy. We call attention to this rare phenomenon because it may pose a diagnostic challenge.

[A woman with gingival enlargement]. / Een vrouw met gezwollen tandvlees.

A 65-year-old female complained of diffuse and rapidly progressive gingival enlargement. Gingival overgrowth can be caused by medication, infections or systemic diseases. In case of generalized, quickly progressive gingival enlargement, acute myeloid leukemia should be considered. Blood results showed an acute myelomonocytic leukemia. Treating the leukemia resolved the symptoms.

Unusual Karyotype in Acute Myelomonocitic Leukemia: A Case Report.

BACKGROUND/AIM: Acute myeloid leukemia is well characterized by chromosomal aberrations that correspond to various subtypes of acute leukemias. The t(8;21)(q22;q22) is a frequent chromosomal abnormality strongly associated with acute myeloblastic leukemia with maturation (AML-M2), but is rarely associated with other subtypes. Translocation involving a third chromosome could produce new genetic rearrangements that lead to leukemogenesis. PATIENTS AND METHODS: Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) were performed to identify the karyotype. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the AML1/ETO transcript. RESULTS/CONCLUSION: We herein report a novel rearrangement with a three-way translocation involving chromosomes 8, 21 and another unknown chromosome, in an 83-year-old female patient diagnosed as AML-M4, with an ALM1/ETO negative transcript. This is an uncommon case of AML-M4 with three-way translocation in a new variant of t(8;21) acute myeloid leukaemia. The detailed mechanism of different phenotype expression is unclear. Further study is needed to identify the leukemogenetic transformation resulting from t(8;21) translocation.

A Case of Granulocytic Sarcoma or Extramedullary Acute Myelomonocytic Leukemia of the Gallbladder.

BACKGROUND Granulocytic sarcoma, or 'chloroma,' due to extramedullary acute myeloid leukemia (AML) or due to acute myelomonocytic leukemia (AML M5), is rare and is associated with a poor prognosis. This report is of a case of granulocytic sarcoma of the gallbladder and describes the approach to diagnosis and treatment. CASE REPORT A 74-year-old Hispanic woman from Ecuador presented to the emergency department with a five-day history of fever, jaundice, and right upper quadrant abdominal pain. The right upper quadrant ultrasound showed a thickened gallbladder wall with cholelithiasis, a positive sonographic Murphy sign, and marked dilatation of the common bile duct, which was up to 17 mm in diameter. Endoscopic retrograde cholangiopancreatography (ERCP) showed purulence and a stone in the common bile duct, which was removed. She underwent laparoscopic cholecystectomy which identified gangrenous cholecystitis. Despite cholecystectomy and treatment with broad-spectrum antibiotics, she remained febrile with a leukocytosis of up to 80,000 cells/µL. Histopathology of the gallbladder showed infiltrating myeloblasts within the mucosa, submucosa, and muscularis consistent with a granulocytic sarcoma associated with gangrenous cholecystitis due to cholelithiasis. Immunohistochemistry, using a panel of antibodies to CD33, CD68, HLA-DR, and lysozyme, supported the diagnosis of granulocytic sarcoma or extramedullary acute myelomonocytic leukemia (AML M5). CONCLUSIONS A rare case of an extramedullary hematologic malignancy, granulocytic sarcoma of the gallbladder is presented, which highlights the importance of timely diagnosis and treatment, due to the high mortality rate associated with granulocytic sarcoma, or extramedullary AML.

Acute myeloid/T-lymphoblastic leukaemia (AMTL): a distinct category of acute leukaemias with common pathogenesis in need of improved therapy.

Advances in the classification of acute leukaemias have led to improved outcomes for a substantial fraction of patients. However, chemotherapy resistance remains a major problem for specific subsets of acute leukaemias. Here, we propose that a molecularly distinct subtype of acute leukaemia with shared myeloid and T cell lymphoblastic features, which we term acute myeloid/T-lymphoblastic leukaemia (AMTL), is divided across 3 diagnostic categories owing to variable expression of markers deemed to be defining of myeloid and T-lymphoid lineages, such as myeloperoxidase and CD3. This proposed diagnostic group is supported by (i) retained myeloid differentiation potential during early T cell lymphoid development, (ii) recognition that some cases of acute myeloid leukaemia (AML) harbour hallmarks of T cell development, such as T-cell receptor gene rearrangements and (iii) common gene mutations in subsets of AML and T cell acute lymphoblastic leukaemia (T-ALL), including WT1, PHF6, RUNX1 and BCL11B. This proposed diagnostic entity overlaps with early T cell precursor (ETP) T-ALL and T cell/myeloid mixed phenotype acute leukaemias (MPALs), and also includes a subset of leukaemias currently classified as AML with features of T-lymphoblastic development. The proposed classification of AMTL as a distinct entity would enable more precise prospective diagnosis and permit the development of improved therapies for patients whose treatment is inadequate with current approaches.

Recurrent somatic JAK-STAT pathway variants within a RUNX1-mutated pedigree.

Germline variants within the transcription factor RUNX1 are associated with familial platelet disorder and acute leukemia in over 40% of carriers. At present, the somatic events triggering leukemic transformation appear heterogeneous and profiles of leukemia initiation across family members are poorly defined. We report a new RUNX1 family where three sisters harboring a germline nonsense RUNX1 variant, c.601C>T (p.(Arg201*)), developed acute myelomonocytic leukemia (AML) at 5 years of age. Whole-exome sequencing of tumor samples revealed all three siblings independently acquired variants within the JAK-STAT pathway, specifically targeting JAK2 and SH2B3 (a negative regulator of JAK2), while also sharing the 46/1 haplotype linked with sporadic JAK2-positive myeloproliferative neoplasms. In-depth chromosomal characterization of tumors revealed acquired copy number gains and uniparental disomy amplifying RUNX1, JAK2 and SH2B3 variants, highlighting the significance of co-operation between these disrupted pathways. One sibling, presenting with myelodysplasia at 14 years, had no evidence of clonal or subclonal JAK2 or SH2B3 variants, suggesting the latter were specifically associated with leukemic transformation in her sisters. Collectively, the clinical and molecular homogeneity across these three young siblings provides the first notable example of convergent AML evolution in a RUNX1 pedigree, with the recurrent acquisition of JAK-STAT pathway variants giving rise to high-risk AML, characterized by chemotherapy resistance and relapse.

Refined diagnostic criteria and classification of mast cell leukemia (MCL) and myelomastocytic leukemia (MML): a consensus proposal.

Mast cell leukemia (MCL), the leukemic manifestation of systemic mastocytosis (SM), is characterized by leukemic expansion of immature mast cells (MCs) in the bone marrow (BM) and other internal organs; and a poor prognosis. In a subset of patients, circulating MCs are detectable. A major differential diagnosis to MCL is myelomastocytic leukemia (MML). Although criteria for both MCL and MML have been published, several questions remain concerning terminologies and subvariants. To discuss open issues, the EU/US-consensus group and the European Competence Network on Mastocytosis (ECNM) launched a series of meetings and workshops in 2011-2013. Resulting discussions and outcomes are provided in this article. The group recommends that MML be recognized as a distinct condition defined by mastocytic differentiation in advanced myeloid neoplasms without evidence of SM. The group also proposes that MCL be divided into acute MCL and chronic MCL, based on the presence or absence of C-Findings. In addition, a primary (de novo) form of MCL should be separated from secondary MCL that typically develops in the presence of a known antecedent MC neoplasm, usually aggressive SM (ASM) or MC sarcoma. For MCL, an imminent prephase is also proposed. This prephase represents ASM with rapid progression and 5%-19% MCs in BM smears, which is generally accepted to be of prognostic significance. We recommend that this condition be termed ASM in transformation to MCL (ASM-t). The refined classification of MCL fits within and extends the current WHO classification; and should improve prognostication and patient selection in practice as well as in clinical trials.