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)