Central nervous system infiltration in acute lymphoblastic leukemia in a dog

Background: Acute lymphoblastic leukemia (ALL) is a malignant neoplasia in which there is proliferation of lymphoid progenitor cells in the bone marrow, blood, and extramedullary sites. This disorder has a fast and progressive development; in dogs, cases of infiltration of ALL cells in the central nervous system (CNS) are uncommon and rare. Diagnosis can be achieved with the help of the clinical history and physical, radiographic, hematological, myelographic, and cerebrospinal fluid (CSF) tests in patients with or without neurological clinical signs. The present report aims to describe a case of ALL and the presence of lymphoblasts in the CSF of a dog with neurological clinical signs. Case: An 8-year-old Lhasa Apso dog was examined at the Veterinary Hospital of Universidade Federal do Paraná, Curitiba campus. At the physical examination, the animal exhibited apathy and paralysis of pelvic limbs, which progressed to tetraplegia. Abdominal palpation revealed presence of hepatosplenomegaly and absence of lymphadenomegaly. No alterations were observed in radiographs of the cervical, thoracic or lumbar spine. A complete blood count revealed presence of non-regenerative anemia (hematocrit = 22%), extreme lymphocytosis (185,229 cells/µL), lymphoblasts at a level of 72% (133,364 cells/µL), and thrombocytopenia (66,000 platelets/µL). The biochemical tests revealed increased alkaline phosphatase (859 IU/L). The levels of alanine aminotransferase, creatinine, urea, total protein, albumin, and globulin were normal. The diagnosis of ALL was achieved with the help of a myelogram. The myelogram findings included 39% of mature lymphocytes and 59% of lymphoblasts exhibiting large size, spherical shape, poorly delimited borders, with a high nucleus/cytoplasm ratio, marked cytoplasmic basophilia, and 2 to 3 evident nucleoli; metarubricytes (1%) and promyelocytes (0.6%) were also observed. The CSF contained an increased number of nucleated cells (27 cells/µL) comprising lymphocytes (43%), macrophages (33%), and segmented neutrophils (24%). Of the 11.6 lymphocytes per µL of CSF, 8.1 were lymphoblasts, which indicates infiltration of ALL cells in the CNS. The animal died one day after collection of bone barrow and CSF. Discussion: Relevant alterations observed in this case included the neurological signs caused by the infiltration of neoplastic cells in the CNS, severe leukocytosis and lymphocytosis, with large amounts of lymphoblasts in the blood and predominance of lymphoblasts in the bone marrow, which are alterations typically found in ALL. The animal also exhibited non-regenerative anemia and thrombocytopenia, which were secondary to infiltration of leukemic cells in the bone marrow. The CSF exhibited pleocytosis (27 cells/ µL), and 30% of the cells observed were lymphoblasts. Lymphoblast infiltration in the CNS of leukemic dogs is rare, and other studies have reported absence of neurological signs or neurological signs different from those observed in the present study. CSF analysis in indicated in cases of leukemia to assess leukemic cell infiltration in the CNS. In the case reported here, the plasma level of alkaline phosphatase was increased (859 IU/L) as a consequence of hepatomegaly and hepatic cholestasis. ALL is a very aggressive, proliferative neoplasia, and the resulting lymphoblasts infiltrated the CNS of the animal. In cases of ALL, performing complete blood count, myelogram, and CSF analysis is indicated whether the patients exhibit neurological signs or not.(AU)

Pancitopenia induzida em um cão pelo uso concomitante de fármacos mielotóxicos / Pancytopenia in a dog induced by concomitant use of myelotoxic drugs

Background: The indiscriminate use of drugs is an issue in Veterinary Medicine, as it has serious consequences for theanimals. Many drugs are myelotoxic and cause a decrease in the production of blood cells, which may be irreversible insome cases. The present work reports a case of pancytopenia induced by the concomitant use of myelotoxic drugs (estrogen, metamizole and phenobarbital) in a dog and describes findings on myelotoxicity, hematological alterations andtreatment success.Case: A 7-year-old Lhasa Apso bitch was referred to the Veterinary Hospital of Federal University of Paraná, Curitibacampus, with hematuria and a history of treatment with phenobarbital [2 mg/kg twice a day (bis in die, BID)], metamizole[25 mg/kg 3 times a day (ter in die, TID)], and use of estrogen hormone (estradiol cypionate). At physical examination, theanimal was normohydrated and exhibited normal palpable lymph nodes, pale mucous membranes, galactorrhea, and a bodytemperature of 36°C. A complete blood count including reticulocyte count and a total plasma protein (TPP) exam wererequested. The results revealed pancytopenia (18% hematocrit, 1,400 total leucocytes/µL, and 22,000 reticulocytes/µL).An abdominal ultrasound exam did not detect any relevant alterations. In view of the results obtained, medullary aplasiawas suspected. A bone marrow aspiration was performed. A myelogram revealed a decrease in cellularity (erythrocyticand granulocytic hypoplasia), with presence of rare erythroid and granulocytic precursors. The diagnosis was medullaryaplasia. The animal was treated, and the evolution of the hematological alterations was monitored. The treatment consistedof administration of erythropoietin (100UI/kg subcutaneously every 48 h), prednisone (2 mg/kg BID), Leucogen (3 mg/kg BID), interferon (0.2 IU/kg BID) and Eritrós Dog Tabs [1 tablet once a day (semel in die, SID)]. After 5 days of treatment, the...

Pancitopenia induzida em um cão pelo uso concomitante de fármacos mielotóxicos / Pancytopenia in a dog induced by concomitant use of myelotoxic drugs

Background: The indiscriminate use of drugs is an issue in Veterinary Medicine, as it has serious consequences for theanimals. Many drugs are myelotoxic and cause a decrease in the production of blood cells, which may be irreversible insome cases. The present work reports a case of pancytopenia induced by the concomitant use of myelotoxic drugs (estrogen, metamizole and phenobarbital) in a dog and describes findings on myelotoxicity, hematological alterations andtreatment success.Case: A 7-year-old Lhasa Apso bitch was referred to the Veterinary Hospital of Federal University of Paraná, Curitibacampus, with hematuria and a history of treatment with phenobarbital [2 mg/kg twice a day (bis in die, BID)], metamizole[25 mg/kg 3 times a day (ter in die, TID)], and use of estrogen hormone (estradiol cypionate). At physical examination, theanimal was normohydrated and exhibited normal palpable lymph nodes, pale mucous membranes, galactorrhea, and a bodytemperature of 36°C. A complete blood count including reticulocyte count and a total plasma protein (TPP) exam wererequested. The results revealed pancytopenia (18% hematocrit, 1,400 total leucocytes/µL, and 22,000 reticulocytes/µL).An abdominal ultrasound exam did not detect any relevant alterations. In view of the results obtained, medullary aplasiawas suspected. A bone marrow aspiration was performed. A myelogram revealed a decrease in cellularity (erythrocyticand granulocytic hypoplasia), with presence of rare erythroid and granulocytic precursors. The diagnosis was medullaryaplasia. The animal was treated, and the evolution of the hematological alterations was monitored. The treatment consistedof administration of erythropoietin (100UI/kg subcutaneously every 48 h), prednisone (2 mg/kg BID), Leucogen (3 mg/kg BID), interferon (0.2 IU/kg BID) and Eritrós Dog Tabs [1 tablet once a day (semel in die, SID)]. After 5 days of treatment, the...(AU)

Aspectos clínicos, laboratoriais e tratamento da leucemia mieloide crônica em cão: relato de caso / Clinical aspects, hematological changes and treatments of chronic myeloid leukemia in dog: case report

O objetivo deste relato é apresentar o caso clínico de uma cadela, sem raça definida, com cinco anos de idade, diagnosticada com leucemia mieloide crônica (LMC). As leucemias são neoplasias malignas que se originam de células precursoras da medula óssea e as consequências podem ser trombocitopenia, anemia, leucocitose persistente e presença de células neoplásicas no sangue. O tratamento de escolha envolve o uso de inibidores de tirosina quinase, porém este não pode ser usado neste caso. Dessa forma a cadela recebeu diferentes protocolos quimioterápicos que incluíram inicialmente hidroxiureia, citarabina, doxorrubicina e prednisona. Devido a remissão parcial dos sinais clínicos e a resposta terapêutica pouco duradoura a essas medicações o protocolo foi alterado para quimioterapia metronômica com clorambucil. O uso desses quimioterápicos não foram eficazes em reduzir a leucocitose e controlar a anemia e trombocitopenia da paciente, devido a ocorrência do surgimento de células imaturas no sangue e resistência aos quimioterápicos. Na ausência da crise e da possibilidade do uso dos inibidores de tirosina quinase, a hidroxiureia permanece sendo o quimioterápico de eleição. O animal apresentou sobrevida de 210 dias, devido a leucocitose e anemia severas pouco responsivas ao protocolo terapêutico utilizado e o surgimento no hemograma de precursores neutrofilicos que ocorreu 46 dias após ao início do tratamento com hidroxiureia.

The aim of this report is to present the clinical case of a five-year-old mixed breed female dog diagnosed with chronic myeloid leukemia (CML). Leukemias are malignant neoplasms that originate from bone marrow precursor cells and the consequences can be thrombocytopenia, anemia, persistent leukocytosis and the presence of neoplastic cells in the blood. The treatment of choice involves the use of tyrosine kinase inhibitors, but it cannot be used in this case. Thus, the dog received different chemotherapy protocols that initially included hydroxyurea, cytarabine, doxorubicin and prednisone. Due to the partial remission of clinical signs and the short-term therapeutic response to these medications, the protocol was changed to metronomic chemotherapy with chlorambucil. The use of these chemotherapeutic agents was not effective in reducing leukocytosis and controlling the patient's anemia and thrombocytopenia, due to the occurrence of immature cells in the blood and resistance to chemotherapeutic agents. In the absence of the crisis and the possibility of using tyrosine kinase inhibitors, hydroxyurea remains the chemotherapy of choice. The animal had a 210-day survival, due to severe leukocytosis and anemia, which were not responsive to the therapeutic protocol used and the appearance in the blood count of neutrophilic precursors that occurred 46 days after the beginning of hydroxyurea treatment.

Aspectos clínicos, laboratoriais e tratamento da leucemia mieloide crônica em cão relato de caso / Clinical aspects, hematological changes and treatments of chronic myeloid leukemia in dog: case report

O objetivo deste relato é apresentar o caso clínico de uma cadela, sem raça definida, com cinco anos de idade, diagnosticada com leucemia mieloide crônica (LMC). As leucemias são neoplasias malignas que se originam de células precursoras da medula óssea e as consequências podem ser trombocitopenia, anemia, leucocitose persistente e presença de células neoplásicas no sangue. O tratamento de escolha envolve o uso de inibidores de tirosina quinase, porém este não pode ser usado neste caso. Dessa forma a cadela recebeu diferentes protocolos quimioterápicos que incluíram inicialmente hidroxiureia, citarabina, doxorrubicina e prednisona. Devido a remissão parcial dos sinais clínicos e a resposta terapêutica pouco duradoura a essas medicações o protocolo foi alterado para quimioterapia metronômica com clorambucil. O uso desses quimioterápicos não foram eficazes em reduzir a leucocitose e controlar a anemia e trombocitopenia da paciente, devido a ocorrência do surgimento de células imaturas no sangue e resistência aos quimioterápicos. Na ausência da crise e da possibilidade do uso dos inibidores de tirosina quinase, a hidroxiureia permanece sendo o quimioterápico de eleição. O animal apresentou sobrevida de 210 dias, devido a leucocitose e anemia severas pouco responsivas ao protocolo terapêutico utilizado e o surgimento no hemograma de precursores neutrofilicos que ocorreu 46 dias(AU)

The aim of this report is to present the clinical case of a five-year-old mixed breed female dog diagnosed with chronic myeloid leukemia (CML). Leukemias are malignant neoplasms that originate from bone marrow precursor cells and the consequences can be thrombocytopenia, anemia, persistent leukocytosis and the presence of neoplastic cells in the blood. The treatment of choice involves the use of tyrosine kinase inhibitors, but it cannot be used in this case. Thus, the dog received different chemotherapy protocols that initially included hydroxyurea, cytarabine, doxorubicin and prednisone. Due to the partial remission of clinical signs and the short-term therapeutic response to these medications, the protocol was changed to metronomic chemotherapy with chlorambucil. The use of these chemotherapeutic agents was not effective in reducing leukocytosis and controlling the patients anemia and thrombocytopenia, due to the occurrence of immature cells in the blood and resistance to chemotherapeutic agents. In the absence of the crisis and the possibility of using tyrosine kinase inhibitors, hydroxyurea remains the chemotherapy of choice. The animal had a 210-day survival, due to severe leukocytosis and anemia, which were not responsive to the therapeutic protocol used and the appearance in the blood count of neutrophilic precursors that occurred 46 days after the beginning of hydroxyurea treatment.(AU)

Aspectos clínicos, laboratoriais e tratamento da leucemia mieloide crônica em cão relato de caso / Clinical aspects, hematological changes and treatments of chronic myeloid leukemia in dog: case report

O objetivo deste relato é apresentar o caso clínico de uma cadela, sem raça definida, com cinco anos de idade, diagnosticada com leucemia mieloide crônica (LMC). As leucemias são neoplasias malignas que se originam de células precursoras da medula óssea e as consequências podem ser trombocitopenia, anemia, leucocitose persistente e presença de células neoplásicas no sangue. O tratamento de escolha envolve o uso de inibidores de tirosina quinase, porém este não pode ser usado neste caso. Dessa forma a cadela recebeu diferentes protocolos quimioterápicos que incluíram inicialmente hidroxiureia, citarabina, doxorrubicina e prednisona. Devido a remissão parcial dos sinais clínicos e a resposta terapêutica pouco duradoura a essas medicações o protocolo foi alterado para quimioterapia metronômica com clorambucil. O uso desses quimioterápicos não foram eficazes em reduzir a leucocitose e controlar a anemia e trombocitopenia da paciente, devido a ocorrência do surgimento de células imaturas no sangue e resistência aos quimioterápicos. Na ausência da crise e da possibilidade do uso dos inibidores de tirosina quinase, a hidroxiureia permanece sendo o quimioterápico de eleição. O animal apresentou sobrevida de 210 dias, devido a leucocitose e anemia severas pouco responsivas ao protocolo terapêutico utilizado e o surgimento no hemograma de precursores neutrofilicos que ocorreu 46 dias

The aim of this report is to present the clinical case of a five-year-old mixed breed female dog diagnosed with chronic myeloid leukemia (CML). Leukemias are malignant neoplasms that originate from bone marrow precursor cells and the consequences can be thrombocytopenia, anemia, persistent leukocytosis and the presence of neoplastic cells in the blood. The treatment of choice involves the use of tyrosine kinase inhibitors, but it cannot be used in this case. Thus, the dog received different chemotherapy protocols that initially included hydroxyurea, cytarabine, doxorubicin and prednisone. Due to the partial remission of clinical signs and the short-term therapeutic response to these medications, the protocol was changed to metronomic chemotherapy with chlorambucil. The use of these chemotherapeutic agents was not effective in reducing leukocytosis and controlling the patient’s anemia and thrombocytopenia, due to the occurrence of immature cells in the blood and resistance to chemotherapeutic agents. In the absence of the crisis and the possibility of using tyrosine kinase inhibitors, hydroxyurea remains the chemotherapy of choice. The animal had a 210-day survival, due to severe leukocytosis and anemia, which were not responsive to the therapeutic protocol used and the appearance in the blood count of neutrophilic precursors that occurred 46 days after the beginning of hydroxyurea treatment.