Marked hyperphosphatasemia associated with an acute leukemia in a Great Dane

This is the report of a 5‐year‐old male neutered Great Dane with an extreme leukocytosis (544.9 × 10⁹ cells/L; RI 5.2–13.9 × 10⁹ cells/L) characterized by highly atypical round cells. Cellular morphologic features such as cytoplasmic membrane blebs, a high nuclear‐to‐cytoplasmic ratio, and nuclear indentations and irregularities and large nucleoli, as well as immunocytochemistry for CD3 and CD79, myeloperoxidase cytochemistry, and clonality testing were not conclusive for myeloid or lymphoid origin. Marked alkaline hyperphosphatasemia was present at the first visit (2783.0 U/L; RI 6–80.0 U/L), followed by a 5‐fold increase (14,000 U/L) a week later, identified as being mostly contributed by the bone‐ALP isoform (11,062 U/L; RI 0–30 U/L). In addition, the atypical leukocytes were strongly positive for cytoplasmic ALP activity. In vitro lysis of a heparin blood sample resulted in a 1.7‐fold increase of ALP activity, supporting the origin of the hyperphosphatasemia at least in part from the leukemic cell population. To the authors’ knowledge, this is a unique case of alkaline hyperphosphatasemia, due at least to a leukemic cell population producing a bone‐ALP isoform, regardless of the exact nature of the leukemia.     

IMAGING FINDINGS IN 14 DOMESTIC FERRETS (MUSTELA PUTORIUS FURO) WITH LYMPHOMA

Lymphoma is the most common malignant neoplasia in domestic ferrets, Mustela putorius furo. However, imaging findings in ferrets with lymphoma have primarily been described in single case reports. The purpose of this retrospective study was to describe imaging findings in a group of ferrets with confirmed lymphoma. Medical records were searched between 2002 and 2012. A total of 14 ferrets were included. Radiographs (n = 12), ultrasound (n = 14), computed tomography (CT; n = 1), and magnetic resonance imaging (MRI; n = 1) images were available for review. Median age at the time of diagnosis was 5.2 years (range 3.25–7.6 years). Clinical signs were predominantly nonspecific (8/14). The time between the first imaging study and lymphoma diagnosis was 1 day or less in most ferrets (12). Imaging lesions were predominantly detected in the abdomen, and most frequently included intra‐abdominal lymphadenopathy (12/14), splenomegaly (8/14), and peritoneal effusion (11/14). Lymphadenopathy and mass lesions were typically hypoechoic on ultrasound. Mild peritoneal effusion was the only detected abnormality in two ferrets. Mild pleural effusion was the most common thoracic abnormality (3/12). Expansile lytic lesions were present in the vertebrae of two ferrets with T3‐L3 myelopathy and the femur in a ferret with lameness. Hyperattenuating, enhancing masses with secondary spinal cord compression were associated with vertebral lysis in CT images of one ferret. The MRI study in one ferret with myelopathy was inconclusive. Findings indicated that imaging characteristics of lymphoma in ferrets are similar to those previously reported in dogs, cats, and humans.     

Leukemic small cell lymphoma or chronic lymphocytic leukemia in a horse

A 16‐year‐old, Irish Draft mare was admitted to the referring veterinarian for an annual health check. A mild generalized lymphadenomegaly was noted. Rectal palpation and transrectal ultrasonographic examination revealed prominent mesenteric lymph nodes. A transcutaneous abdominal ultrasonographic evaluation was unremarkable. A CBC revealed a marked leukocytosis (63.06 × 10³/μL) and lymphocytosis (58.2 × 10³/μL) due to increased numbers of small lymphocytes. No evidence of anemia or thrombocytopenia was found and neutrophil counts were low‐normal. Cytologic examination of fine‐needle aspirates of multiple lymph nodes and a bone‐marrow aspirate revealed the presence of a monomorphic population of small lymphocytes similar to those observed in the peripheral blood, suggesting a leukemic small cell lymphoma (SCL) or chronic lymphocytic leukemia (CLL). As the lymphadenomegaly and peripheral blood lymphocytosis were present simultaneously, the distinction between these 2 conditions was not possible. Immunophenotyping by immunocytochemistry and flow cytometry of the lymphoid cells in peripheral blood determined a T‐cell phenotype. As the horse was clinically stable, no treatment was initiated, but regular examinations were undertaken. A CBC repeated 120 days after the diagnosis showed a marked lymphocytosis (157.6 × 10³/μL) with no evidence of anemia or other cytopenias. The horse was euthanized 194 days after the initial diagnosis. Histopathology and immunohistochemistry of submandibular lymph nodes and bone marrow confirmed the diagnosis of leukemic SCL or CLL, and a T‐cell phenotype. SCL and CLL are rare in horses; previous immunohistochemical studies determined that the T‐cell phenotype is predominant. To the authors' knowledge, this is the first report of the combined use of immunocytochemistry and flow cytometry in a horse with leukemic SCL or CLL.     

Frequency of a FAS ligand gene variant associated with inherited feline autoimmune lymphoproliferative syndrome in British shorthair cats in New Zealand

Abstract

AIMS

To determine the frequency of the FAS-ligand gene (FASLG) variant associated with feline autoimmune lymphoproliferative syndrome (FALPS) and the proportion of carriers of the variant in three British shorthair (BSH) breeding catteries in New Zealand.     

Outcome and failure patterns of localized sinonasal lymphoma in cats treated with first‐line single‐modality radiation therapy: A retrospective study

Failure rate and site are not well defined in localized sinonasal lymphoma in cats treated with radiotherapy. In this study, we describe (a) failure pattern, (b) outcome, (c) influence of previously reported prognostic variables on the outcome in cats with suspected localized sinonasal lymphoma. In this multi‐institutional retrospective study, we included 51 cats treated with single‐modality radiotherapy. Cats were irradiated using 10x4.2Gy (n = 32), 12x3Gy (n = 11) or 5x6Gy (n = 8). Regional lymph nodes were prophylactically irradiated in 24/51 cats (47.1%). Twenty‐five cats (49.0%) developed progressive disease: progression was local (nasal) in five (9.8%), locoregional (nodal) in two (3.9%), local and locoregional in three (5.9%), systemic in nine (17.6%) and both local and systemic in six cats (11.8%). No cat receiving prophylactic nodal irradiation had progression in the locoregional lymph nodes. The median time to progression was 974 days (95%CI: 283;1666), with 58% and 53% of cats free of progression at 1 and 2 years, respectively. Median overall survival was 922 days (95%CI: 66;1779) with 61% and 49% alive at 1 and 2 years, respectively. Half of the cats that died of relapse/progression (13/26) died within 6 months of treatment, suggesting possible shortcomings of staging, rapid dissemination of disease or sequential lymphomagenesis. None of the prognostic factors evaluated were predictive of outcome (prednisolone use, anaemia, nasopharyngeal involvement, modified canine Adams tumour stage, protocol, total dose). Radiotherapy is an effective treatment for localized sinonasal lymphoma with a long time to progression. However, in one‐third of the cats, systemic disease progression occurs soon after radiotherapy.     

Antibodies in carrier wildebeest to the lymphoproliferative herpesvirus of malignant catarrhal fever

Six types of antibody to malignant catarrhal fever virus (MCFV) were measured in 132 sera collected from Wildebeest in Kenya Masailand. The titre of all types of antibody declined slowly with increasing age of the wildebeest. A significantly greater proportion of wildebeest calves had higher titres of antibodies to MCFV early antigens, IgM antibodies to MCFV late antigens and complement-fixing antibodies, than did older animals. One seronegative calf, reared in isolation without colostrum, became seropositive 4 1/2 weeks after birth but did not show any clinical signs indicative of MCFV infection. Similarities between MCFV infection of wildebeest calves and other inapparent infections with lymphoproliferative herpesviruses are discussed.