Sellar xanthogranuloma in a dog.

A 7-year-old, intact male standard Poodle dog with hypothyroidism and atypical hyperadrenocorticism developed acute signs of lethargy, weakness, inappetence, vomiting, and diarrhea. Clinical signs progressed to hind limb proprioceptive deficits, aggressive behavior with obtundation, and an equivocal seizure. Necropsy revealed a mass in the sellar region that histologically consisted of multinucleated giant cells, macrophages, and hemosiderin-laden macrophages with fewer lymphocytes and plasma cells admixed with large regions of cholesterol cleft deposition, fibrin, and prominent Rosenthal fibers. Pituitary tissue was not identified on gross or histologic examination, but the mass was partially bordered by epithelial cells. The histologic characteristics are similar to changes described in the human medical literature as xanthogranuloma of the sellar region and xanthogranulomatous hypophysitis.

Pulmonary Paecilomyces lilacinus Infection in a Cat.

A 6-year-old, spayed female domestic shorthair cat was referred for an intermittent cough and wheezing of 3 to 4 months' duration. Thoracic radiography revealed atelectasis of the right middle and caudal lung lobes with hyperinflation of the accessory lobe, consistent with bronchial obstruction. Bronchoscopy confirmed a narrowing of the right mainstem bronchial lumen; however, positive-pressure ventilation resulted in a severe pneumothorax. A lateral thoracotomy and right caudal lung lobectomy resulted in complete resolution of the pneumothorax and respiratory signs. Histopathology and culture of the lung revealed Paecilomyces lilacinus. The cat was placed on itraconazole therapy for 6 months. Since dismissal from the hospital, the cat has not exhibited clinical evidence of wheezing, coughing, or dyspnea and is neurologically normal.

Indices of urine N-acetyl-beta-D-glucosaminidase and gamma-glutamyl transpeptidase activities in clinically normal adult dogs.

OBJECTIVE: To establish reference ranges for indices of urine N-acetyl-B-D-glucosaminidase (NAG) and gamma-glutamyl transpeptidase (GGT) activities in clinically normal adult dogs. ANIMALS: 38 dogs. PROCEDURES: Each dog underwent a physical examination, CBC, serum biochemical analysis, urinalysis, and serologic testing for heartworm antigen and antibodies against Ehrlichia canis and Borrelia burgdorferi. Activities of NAG and GGT in urine were evaluated, and values of the respective indices were determined as urine NAG or GGT activity (U/L) divided by urine creatinine concentration (g/L). RESULTS: All dogs were considered clinically normal. A 90% prediction interval based on the 5th and 95th percentiles for GGT and NAG index values from both sexes was used to establish the reference ranges for dogs: 1.93 to 28.57 U/g and 0.02 to 3.63 U/g, respectively. Between males and females, urine NAG index differed significantly, whereas urine GGT index did not. When accounting for sex differences, reference ranges for the urine NAG index in males and females were 0.02 to 3.65 U/g and 0.02 to 2.31 U/g, respectively. Changes in urine pH significantly affected the urine GGT index but not the urine NAG index. Neither index changed significantly with changes in body surface area. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that increases in urine NAG and GGT indices allow for earlier detection of renal tubular damage in dogs. Such early detection would enable adjustment of the clinical management of affected dogs to decrease morbidity and death rates associated with acute tubular injury and acute tubular necrosis.

Dendritic cell leukemia in a Golden Retriever.

An 8-year-old castrated male Golden Retriever was evaluated for decreased appetite, lethargy, and labored breathing of 1-week duration. Bilateral pulmonary infiltrates, hepatomegaly, and splenomegaly were present. Results of a CBC revealed marked leukocytosis (62,600/microL; reference interval 4000-15,500/microL) and large numbers of atypical cells (30,700/microL) with abundant cytoplasm. There was no concurrent anemia, neutropenia, or thrombocytopenia. Morphology of the atypical cells was most consistent with a histiocytic origin. Similar cells were identified in bone marrow aspirates, and were morphologically suggestive of the macrophage variant of disseminated histiocytic sarcoma. However, flow cytometry of the abnormal circulating cells revealed CD1c, CD11c, and major histocompatibility complex (MHC) Class II expression without expression of CD11d or lymphoid markers, consistent with myeloid dendritic antigen-presenting cells. At necropsy, the splenic architecture was effaced by neoplastic histiocytes that were also infiltrating lung, liver, an abdominal lymph node, myocardium, an bone marrow. Immunohistochemistry of the splenic neoplastic cells confirmed dendritic cell origin (CD1c+, CD11c+, MHC II+, no expression of CD11d and lymphoid markers). To the authors' knowledge, this is the first report of canine dendritic cell leukemia-in this instance accompanied by marked tissue infiltration.

B-cell lymphoma in a dog with ehrlichiosis (Ehrlichia canis) and systemic histoplasmosis (Histoplasma capsulatum).

A mixed breed dog treated for ehrlichiosis and systemic histoplasmosis developed a refractory thrombocytopenia. When an abdominal mass was detected, exploratory laparotomy and biopsies confirmed lymphoma, which on immunohistochemical stains was determined to be of B-cell origin. Conceivably, the B-cell lymphoma in this dog was associated with chronic inflammation from ehrlichiosis, histoplasmosis, or both.