Leukemia cutis - A case of cutaneous manifestation of acute monoblastic leukemia.

Leukemia cutis is a comprehensive terminology for dermal manifestations of any type of leukemia either with accompanied or antecedent blood or bone marrow involvement. Although both myeloid and lymphoid neoplastic leukocytes can infiltrate the skin, the frequency is higher among children with congenital myeloid leukemia. However, the underlying pathogenesis of dermal tropism is not yet established. Clinical manifestation varies regarding appearance, site, and numbers. Skin biopsy is essential for the early establishment of the diagnosis and to guide for further testing and categorical management. We report the case of acute myeloid leukemia-cutis in a 22-year-old female where cutaneous manifestation preceded the hematological diagnosis of systemic leukemia.

Acute monocytic leukemia with KMT2A::LASP1 developed 9 months after diagnosis of acute megakaryoblastic leukemia in a 2-year-old boy.

Acute myeloid leukemia (AML) is known as one of the subsequent malignant neoplasms that can develop after cancer treatment, but it is difficult to distinguish from relapse when the preceding cancer is leukemia. We report a 2-year-old boy who developed acute megakaryoblastic leukemia (AMKL, French-American-British classification [FAB]: M7) at 18 months of age and achieved complete remission with multi-agent chemotherapy without hematopoietic stem cell transplantation. Nine months after diagnosis and 4 months after completing treatment for AMKL, he developed acute monocytic leukemia (AMoL) with the KMT2A::LASP1 chimeric gene (FAB: M5b). The second complete remission was achieved using multi-agent chemotherapy and he underwent cord blood transplantation 4 months after AMoL was diagnosed. He is currently alive and disease free at 39 and 48 months since his AMoL and AMKL diagnoses, respectively. Retrospective analysis revealed that the KMT2A::LASP1 chimeric gene was detected 4 months after diagnosis of AMKL. Common somatic mutations were not detected in AMKL or AMoL and no germline pathogenic variants were detected. Since the patient's AMoL was different from his primary leukemia of AMKL in terms of morphological, genomic, and molecular analysis, we concluded that he developed a subsequent leukemia rather than a relapse of his primary leukemia.

Monoblastic leukemia (M5a) with chronic basophilic leukemia in a cat.

A cat was presented with depression and anorexia. The complete blood cell count (CBC) revealed non-regenerative anemia (PCV, 8.5%), marked thrombocytopenia (2,400/µl), and leukocytosis (32,090/µl). In the peripheral blood, proliferation of blast cells (85%; 27,276/µl) and basophils (7.7%; 2,460/µl) was observed. Bone marrow aspirate showed hyperplasia with 8.8% blasts and 90.2% basophils of all nucleated cells. The blast cells were negative for myeloperoxidase staining and positive for alpha-naphthol butyrate esterase staining, indicating the agranular blasts are monoblasts. Thus, acute monoblastic leukemia (M5a) with chronic basophilic leukemia was diagnosed. Basophils accounted for more than 40% of the bone marrow, and we diagnosed secondary basophilic leukemia. Secondary basophilic leukemia should be included in the differential list when abnormal basophil increases are observed in feline bone marrow.

Bilateral Pseudo-hypopyon as Presenting Symptom of Acute Monocytic Leukemia in an 8-Month-Old Infant.

A previously healthy 8-month-old female infant presenting with lethargy and bilateral eye redness and cloudiness had bilateral hypopyon uveitis, which persisted despite topical steroids. Cytology of the anterior chamber and cerebrospinal fluid and flow cytometry of cerebrospinal fluid revealed malignant cells consistent with acute monocytic leukemia. Bone marrow aspirates and biopsies showed no evidence of disease. She was treated with systemic and intrathecal chemotherapy, with subsequent remission and resolution of pseudo-hypopyon. Anterior chamber involvement is a rare presentation of acute myeloid leukemia and may indicate concurrent central nervous system involvement. This has important therapeutic implications, because additional treatment modalities such as intrathecal chemotherapy, local chemotherapy, and ocular radiation may be required to overcome the "pharmacologic sanctuary" created by the blood-ocular barrier. [J Pediatr Ophthalmol Strabismus. 2021;58(5):e30-e33.].

Leucemia monoblastica aguda: complicaciones y respuesta a la quimioterapia de inducción. Reporte de cado / Acute monoblastic leukemia: complications and response to induction chemotherapy. Case report

La leucemia Monoblástica o Monocítica Aguda, es similar a otros subtipos de leucemias agudas, algunas peculiaridades que las diferencian son la hiperleucocitosis, infiltración extramedular y coagulación intravascular diseminada. El tratamiento de inducción se basa en drogas antracíclicas combinadas con citarabina; las complicaciones pueden ser fatales y la sobrevida a largo plazo se estima en 25% a 40%. Objetivo: documentar la r espuesta y complicaciones del tratamiento (quimioterapia) de inducción en la leucemia monoblástica aguda. Presentación de caso clínico: mujer de 34 años, acude con cuadr o inicial de congestión nasal bilateral y fiebre; examen físico normal, a excepción de equimosis en sitios de venopunción, el hemograma reveló anemia, leucocitosis y trombocitopenia. El frotis de sangre periférica, la biopsia y aspirado de médula ósea, fueron característicos de leucemia mieloide aguda tipo monocítica. Durante el tratamiento se administró dos ciclos de quimioterapia de inducción y coadyuvantes con base en hemoderivados, factor estimulante de colonias de granulocitos, antieméticos, antibióticos y antimicóticos. Complicaciones: se presentó toxicidad manifiesta por náuseas y vómitos grado II, mucositis, pérdida de peso y alopecia total, alteraciones hematológicas y complicaciones infecciosas grado IV. Se obtuvo remisión hematológica completa. Conclusión: es posible tr atar pacientes que sufr en leucemia monoblástica aguda tipo M5, en nuestro 1Universidad Nacional Autónoma de Honduras, Facultad de Ciencias Médicas, Tegucigalpa, Honduras. 2Laboratorios Molina, Tegucigalpa, Honduras. 3Investigador Independiente, Western International School, San Pedro Sula, Honduras. Autor de correspondencia: José Angel Sánchez N., jose.skiro@gmail.com Recibido: 03/12/2020 Aceptado: 15/05/2021 medio, con quimioterapia agresiva y obtener remisión hematológica completa. La identificación temprana de complicaciones y manejo oportuno es fundamental para evitar consecuencias fatales...(AU)

A case of acute monocytic leukemia (AMoL or AML-M5) in an adult FeLV/FIV-positive cat.

A 7-year-old castrated male domestic shorthair cat was presented for evaluation of decreased appetite and respiratory signs. A CBC run on presentation revealed severe nonregenerative anemia, thrombocytopenia, and leukocytosis characterized by a prominent population of blasts, having morphologic features suggestive of a monocytic lineage. The cat tested positive for FIV, FeLV, Mycoplasma haemominutum, and only mild abnormalities were identified on the chemistry panel. Bone marrow biopsies were obtained to investigate the bicytopenia and the possibility of a hematopoietic neoplasm. Although the bone marrow aspirate was nondiagnostic, the core biopsy was markedly hypercellular with a population of blasts, largely replacing the normal hematopoietic tissue. Immunohistochemical staining revealed that the blasts were CD3-negative, Pax5-negative, dimly CD18-positive, and moderately positive for Iba1. These findings, in addition to the prominent monocytic differentiation seen in peripheral blood, supported a diagnosis of acute monocytic leukemia. Palliative antiviral and antibiotic treatment and blood transfusion were performed. The patient was discharged on his fourth day of hospitalization. However, 15 days following discharge, the cat was euthanized due to the worsening of his systemic signs. This report discusses the classifications of myeloid leukemias, implications of infectious diseases in the pathogenesis of neoplasia in cats, and the use of Iba1, a "pan-monocytic/histiocytic" marker, in the diagnosis of acute leukemia.

HEMOPHAGOCYTOSIS BY BLASTS IN A CHILD WITH ACUTE MONOCYTIC LEUKEMIA AFTER CHEMOTHERAPY.

OBJECTIVE: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. CASE DESCRIPTION: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. COMMENTS: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient's karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

Leukemia Cutis With Histopathologic and Immunophenotypic Features Resembling S100-Negative CD1a-Positive Cutaneous Histiocytosis.

ABSTRACT: S100-negative CD1a-positive cutaneous histiocytosis is an exceedingly rare histiocytosis that is defined histopathologically by a dense dermal infiltrate of ovoid mononuclear cells with grooved nuclei and ample cytoplasm with variable nuclear atypia and mitoses that are immunohistochemically positive for CD1a and negative for S100 and CD207 (langerin). The histogenesis of S100-negative CD1a-positive histiocytosis is unclear, and its precursor cell has yet to be characterized. Although all cases thus far have been described as benign and occasionally self-resolving, the clinical course and outcome of this disease are not fully understood. This case expands the spectrum of disease associated with S100-negative CD1a-positive histiocytosis given its malignant course.

Hemophagocytosis by blasts in a child with acute monocytic leukemia after chemotherapy / Hemofagocitose por células blásticas em paciente pediátrico com leucemia monocítica aguda após quimioterapia

ABSTRACT Objective: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. Case description: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. Comments: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient's karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

RESUMO Objetivo: Descrever um caso de um paciente pediátrico que apresentou linfo-histiocitose hemofagocítica (LHH) associada à leucemia monocítica aguda pós-quimioterapia, com hemofagocitose causada pelas próprias células leucêmicas. Descrição do caso: Em um hospital universitário do Sul do Brasil, uma menina de três anos foi diagnosticada com leucemia monocítica aguda com cariótipo normal. Após receber protocolo quimioterápico, atingiu remissão seis meses depois do início do tratamento, recaíndo quatro meses após com um cariótipo complexo envolvendo ambos os cromossomos, 8p e 16q. A medula óssea mostrava-se infiltrada por células blásticas vacuolizadas com aspecto monocítico, com evidências de hemofagocitose. A criança apresentou um declínio clínico progressivo e dois meses após a recaída foi a óbito. Comentários: A LHH é uma condição inflamatória rara e agressiva caracterizada por citopenias, hepatoesplenomegalia, febre e hemofagocitose na medula óssea, linfonodos, baço e fígado. A LHH associada a doenças malignas, embora seja uma condição rara, é potencialmente fatal. A paciente deste caso apresentou cinco dos oito critérios estabelecidos para o diagnóstico de LHH. A evolução do cariótipo do paciente, independentemente do perfil do diagnóstico, pareceu ser secundária ao tratamento da leucemia monocítica aguda, sendo que a instabilidade citogenética pode ter influenciado o comportamento atípico observado nas células leucêmicas. Este é um dos raros casos de LHH em uma criança com leucemia monocítica aguda.

Rare Case of Diffuse Large B-Cell Lymphoma Mimicking Acute Monocytic Leukemia, Associated with Complex Karyotype.

OBJECTIVE: Diffuse Large B-Cell Lymphoma (DLBCL), NOS, constitutes 25-35% of adult non-Hodgkin lymphomas in developed countries, and a higher percentage in developing countries; older people are prone to the disease. Three frequent morphological variants have been recognized, including centroblastic, immunoblastic, and anaplastic variants. However, there are still other rare morphological variants of DLBCL, presenting challenge in diagnosis and treatment. CASE PRESENTATION: A 62-year-old woman sought medical attention with a previous 6-month history of intermittent fever and leukocytosis. Bone marrow (BM) aspiration presented AML with acute monocytic leukemia-like morphologic features. The results of the immunophenotypic analysis suggested mature B cell lymphoma without obvious subtype characteristics. Lymph node biopsy indicated DLBCL of non-germinal centre B-cell subtype (n-GCB). Cytogenetic analysis of the BM cells revealed a 46,XX, trp(1)(q21q32),del(7)(q32q36),t(9;14)(p13;q32) [4]/46,XX [16] karyotype. The patient was diagnosed with EBV-positive DLBCL, NOS based on the combination of lymph node biopsy, clinical, cytological, immunophenotypic, and cytogenetic analyses. CONCLUSION: To date, no case reports of a patient diagnosed with DLBCL mimicking acute monocytic leukemia with complex karyotype have been reported. We present the case given its rarity, easy misdiagnosis, and poor prognosis. The case highlights the importance of awareness about the rare morphological variant to laboratory staff and hematologists.

Acute monoblastic leukemia in a feline leukemia virus-negative cat.

A 12-year-old female domestic short-haired cat was presented due to weight loss, anorexia, and tachypnea. Complete blood count revealed severe anemia, leukocytosis with massive undifferentiated blast cells, and thrombocytopenia. Bone marrow aspiration showed acute myeloid leukemia, subclassified as monoblastic leukemia (M5a) based on the outcomes of the cytochemistry examinations. The SNAP feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) test using whole blood was negative. In addition, FeLV/FIV proviral polymerase chain reaction test using bone marrow aspirate was also negative. Although the cat was treated with doxorubicin, cytosine arabinoside, and prednisolone, anemia did not improve without blood transfusion. The owner declined further treatment after 2 months, and the cat died a few days later.

Development of myelofibrosis and acute monocytic leukemia in a patient with hereditary spherocytosis: A case report.

INTRODUCTION: Common symptoms of hereditary spherocytosis (HS) include intermittent jaundice and splenomegaly. Here, we present an unusual clinical course wherein a patient with HS treated with splenectomy developed secondary myelofibrosis and acute monocytic leukemia (M5). PATIENT CONCERNS: After presenting with paleness, fatigue and jaundice, the patient was diagnosed with HS. After splenectomy, follow-up testing, including bone marrow biopsy, revealed myelofibrosis. Subsequently, the patient exhibited blood cell abnormalities consistent with M5. DIAGNOSIS: M5 comorbid with myelofibrosis and a history of HS. INTERVENTIONS: HS was treated with splenectomy. Myelofibrosis was treated with hydroxyurea. The patient refused chemotherapy for M5 and was discharged. He was maintained on hydroxyurea and received periodic blood product transfusions with regular routine blood test monitoring. OUTCOMES: Because of intracranial hemorrhage, the patient died on May 17, 2018, a little >10 months after being diagnosed with leukemia. CONCLUSION: The present patient developed M5 while undergoing treatment for myelofibrosis and after undergoing splenectomy for HS, raising the question of whether these conditions might be associated. Examination of this question will require the analysis of additional cases.

Ocular infiltration as initial presentation of acute monocytic leukaemia transformed from chronic myelomonocytic leukaemia associated with BRAF V600E mutation.

Acute monocytic leukaemia (French-British-American classification: AML-M5b) is characterised by a predominance of cells of the monocytic lineage on bone marrow examination. Furthermore, a discerning feature is its tendency for tissue infiltration. While gum hypertrophy and hepatosplenomegaly are common, ocular involvement is rare. Here, we present a case of a 75-year-old man referred with proptosis and monocytosis-subsequently diagnosed as AML-M5b, whose disease course was distinguished by extensive tissue invasion (ocular, pulmonary, liver, spleen). Cytogenetics and molecular tests were consistent with blastic transformation of previously undiagnosed chronic myelomonocytic leukaemia, supported by the presence of long-standing, low-grade monocytosis. Notably, a BRAF V600E mutation was also detected-an oncogenic driver previously reported in de novo and therapy-related, but not chronic myelomonocytic leukaemia-transformed, AML-M5b. While an initial response to cytoreductive treatment was observed, his tissue-invasive disease soon progressed with worsening pulmonary infiltrates, disseminated intravascular coagulation and renal failure, resulting in death.