Cytology and the cell block method in diagnostic characterization of canine lymphadenopathy and in the immunophenotyping of nodal lymphoma

Minimally invasive techniques used to evaluate canine peripheral lymphadenopathy (PLN), including fine needle aspiration biopsy with cytological evaluation (FNAB‐C) and flow cytometry (FC), have benefits and limitations. The cell block (CB) method is an alternate processing technique in which fine needle aspirate biopsy samples are concentrated, fixed, and embedded in paraffin for routine histological processing/staining. Utilizing three observers, we determined the diagnostic value of the CB in evaluating canine PLN across six categories (non‐diagnostic, reactive, inflammatory/infectious, probable lymphoma and lymphoma, metastatic neoplasia) and correlated findings to immunophenotypic and clonal antigen receptor rearrangement results in canine nodal lymphoma. Eighty‐five paired FNAB‐C and CB samples were evaluated from canine patients presenting to the University of Minnesota Veterinary Oncology or Internal Medicine services. Diagnostic quality samples were obtained in 55/85 (65%) CB and 81/85 (95%) FNAB‐C samples, respectively, and nodal pathology impacted CB diagnostic yield. Overall percent agreement between diagnostic‐quality FNAB‐C and CB samples was 86%, but increased to 95% if the categories of lymphoma and probable lymphoma were combined. There was 100% agreement for both the diagnoses of metastatic neoplasia and reactive lymph nodes and 92% agreement for the diagnosis of lymphoma/probable lymphoma. Using immunohistochemistry (IHC), CB samples correctly immunophenotyped 22/23 (96%) cases of B‐cell lymphoma, but only 1/6 (17%) cases of T‐cell lymphoma. IHC was not completed on nine cases of lymphoproliferative disease because of insufficient cellularity. When the CB method (CBM) yielded diagnostic quality samples there was good to excellent agreement with FNAB‐C samples and CB samples were suitable for some IHC tests.     

CT features of malignant tubular genital tract tumors in seven goats

Neoplasia of the tubular genital tract in goats, while rarely described, is most commonly reported as uterine adenocarcinoma, leiomyoma, or leiomyosarcoma. In this retrospective, single-center, case series, medical records were searched for goats with a computed tomography (CT) diagnosis of tubular genital mass and a definitive histologic (surgical biopsy or necropsy) diagnosis of malignant neoplasia. Data recorded from CT images were presence of peritoneal/retroperitoneal fluid, urinary tract obstruction, abdominal lymphadenomegaly, additional abdominal nodules/masses, and pulmonary nodules. For masses, maximum cross-sectional area, contrast enhancement, and uterine luminal fluid accumulation were also recorded. Seven goats met the inclusion criteria (leiomyosarcoma n = 5, adenocarcinoma n = 2). Both goats with adenocarcinoma had upper urinary tract obstruction, moderate to severe regional lymphadenopathy, peritoneal fluid, and peritoneal or hepatic nodules/masses; one goat with adenocarcinoma was discharged and subsequently euthanized, and the other had palliative mass debulking and was lost to follow up. Goats with leiomyosarcoma had infrequent, mild peritoneal fluid and mild sublumbar lymphadenopathy. Of the goats with leiomyosarcoma, two were euthanized at or near the time of CT imaging, two were euthanized at the time of surgery due to perceived mass non-resectability, and one had mass regression approximately four months post ovariohysterectomy but was subsequently lost to follow up. Five goats had pulmonary nodules, three of which had pathologic confirmation (pulmonary metastasis in a single patient with adenocarcinoma, and lungworm granulomas in two goats with leiomyosarcoma). Severe sublumbar lymphadenopathy and obstructive uropathy were sequelae in the two caprine patients with genital adenocarcinoma, and in none with leiomyosarcoma.     

NEEDLE-TRACT IMPLANTATION FOLLOWING US-GUIDED FINE-NEEDLE ASPIRATION BIOPSY OF TRANSITIONAL CELL CARCINOMA OF THE BLADDER, URETHRA, AND PROSTATE

Localized tumor implantation of the ventral abdominal wall was found at 2, 5, and 8 months following percutaneous ultrasound-guided fine-needle aspiration biopsy (FNAB) of transitional carcinoma of the bladder, urethra, or prostate in 3 dogs. To our knowledge this complication has not been reported in dogs following FNAB. Despite the rarity of needle-tract implantation, the potential for this complication with transitional cell carcinomas is apparently not negligible and warrants consideration. We recommend traumatic urethral catheterization to obtain a cytologic diagnosis of potential transitional cell carcinomas of the lower urinary tract or prostate whenever possible until more information becomes available. However, needle-track implantation is so rare that it should not influence the decision to perform a percutaneous FNAB if the urethra cannot be catheterized.     

Carcinoma in the urinary bladder of a cat: cytologic findings and a review of the literature

Percutaneous fine needle aspiration biopsy (FNAB) was used to diagnose a urinary bladder carcinoma in an aged cat. The cytologic appearance of specimens collected initially was similar to that reported for canine transitional cell carcinoma. However, impression smears of the tumor made at necropsy 7 weeks later consisted predominantly of atypical squamous epithelial cells compatible with squamous cell carcinoma. Histologically, the malignancy was noted to have intermixed areas of abnormal squamous and transitional cell proliferation. The neoplasia was interpreted as a transitional cell carcinoma with extensive transformation to squamous cell carcinoma. This report examines the use and limitations of FNAB in the diagnosis of feline urinary bladder carcinoma and the incidence and behavior of these tumors in the cat.     

Presumed acquired dynamic pectus excavatum in a cat

An 11-year-old, spayed female American domestic shorthair cat was presented with open-mouth breathing and dyspnea due to respiratory tract disease. Radiographically, there was thickening of the retropharyngeal soft tissue and soft palate, focal pulmonary change, and severe pectus excavatum (PE), best seen on the left lateral view. Repeat thoracic radiographs 4 months later showed persistent PE, but only on the right lateral view; PE was absent on the left lateral view. The dynamic component of the observed PE was presumably acquired secondary to chronic upper respiratory disease and/or concurrent increased pliability of the thoracic wall from prolonged prednisolone treatment.     

Ocular manifestations of a metastatic adenocarcinoma in a horse

A 10‐year‐old German Warmblood gelding was referred to the Equine Department of the Vetsuisse Faculty, University of Zurich, Switzerland, for an iris mass OD, lethargy, intermittent fever, and coughing. Ophthalmic examination revealed a 7 × 9 mm raised, fleshy, whitish to pinkish, vascularized iris mass at the 2 o`clock position OD. Fundic examination showed multifocal round, brown to black, slightly raised lesions with indistinct margins and a surrounding hyperreflective zone OU. Physical examination revealed a temperature of 39.2 °C, sinus tachycardia, preputial and ventral edema, and an enlarged right mandibular lymph node. Results of a complete blood count and plasma biochemical profile showed mild anemia, leukocytosis, and thrombocytopenia. Severe splenopathy, moderate splenomegaly, and severe pulmonary pathology with nodules and large areas of consolidated lung parenchyma were observed on abdominal ultrasound and thoracic radiographs, respectively. Fine needle aspirates of the enlarged mandibular lymph node showed malignant epithelial neoplastic cells. The horse was euthanized because of the poor prognosis and subsequently underwent postmortem examination. Macroscopic necropsy and histopathology revealed an adenocarcinoma of suspected pulmonary origin with involvement of eyes, heart, liver, kidneys, spleen, diaphragm, skeletal muscles, mandibular, pulmonary, and internal iliac lymph nodes. Metastatic adenocarcinoma should be considered as a differential diagnosis in horses with iris masses, multifocal chorioretinal infiltrates, and clinical signs that conform to a paraneoplastic syndrome.     

Thoracic wall and pulmonary trauma in dogs sustaining fractures as a result of motor vehicle accidents

The records of 267 dogs seen at the University of Minnesota Veterinary Teaching Hospital for fractures resulting from motor vehicle accidents were examined to determine the prevalence and types of thoracic wall and pulmonary trauma associated with such cases. Results were analyzed for type and prevalence of thoracic wall and pulmonary injury, and for the prevalence of such injury in dogs with and without extrathoracic injury, in dogs with fractures of single vs multiple bones, in dogs with single fractures of specific bones, in dogs with fractures in the cranial vs the caudal one half of the body, and in dogs with fractures ipsilateral vs contralateral to thoracic injury. The overall prevalence of thoracic wall and pulmonary trauma was 38.9%; pulmonary contusions, pneumothorax, and fractured ribs were the most common injuries. More than 1 type of thoracic wall or pulmonary injury was diagnosed in 57.7% of the cases. Of the dogs with thoracic injury, 24% also had extrathoracic injuries; 16.5% of dogs without thoracic injury had extrathoracic injuries, not including fractures. Of the dogs with fractures of 1 bone, 36.3% had thoracic injuries. Of the dogs with fractures of more than 1 bone, 42.3% had thoracic injuries. The prevalence of thoracic wall and pulmonary trauma was significantly associated with the site of the fracture (cranial vs caudal and ipsilateral vs contralateral); significant association with the specific bone fractured was also seen for some fractures.     

Computed tomographic characteristics of cavitary pulmonary adenocarcinoma in 3 dogs and 2 cats

Cavitary pulmonary lesions can result from the localized breakdown of pulmonary parenchyma or be caused by the expulsion of a necrotic part of a mass. The objectives of this study were to describe the clinical and computed tomographic characteristics for cases of cavitary pulmonary adenocarcinoma and find associations between the features and those identified in human pulmonary cavitary soft tissue lesions. Five cases were identified that had a cavitary pulmonary mass on thoracic computed tomography (CT) and histopathology of the lesions. Three dogs and 2 cats had cavitary pulmonary adenocarcinoma. Common features of CT in these cases included lesions in the caudal lung lobes, lobular and spiculated lesion margins, air bronchograms within the mass, pleural tags, heterogeneous contrast enhancement, and ground glass opacity in the surrounding parenchyma. The findings of this case series suggest there are similarities in the CT characteristics of malignancy in human and animal cavitary pulmonary masses.     

Localised radiotherapy for a ferret with possible anal sac apocrine adenocarcinoma

A seven-year-old, neutered male ferret was referred to our hospital with two perianal masses (2.4x3.0 and 2.4x3.5 cm, respectively) that had recurred after initial surgical excision. Complete resection of the masses was impossible as there was deep invasion along the rectum. On histopathology, the masses were diagnosed as apocrine adenocarcinoma possibly of anal gland origin based on tumour location. There was marked response to localised radiotherapy using an orthovoltage unit at 4 Gy, twice weekly. No visible mass was detectable after six doses of radiation. However, at that time, pleural effusion was diagnosed and radiotherapy was discontinued. Cytology of a sample of the pleural effusion suggested mesothelioma, and no obvious pulmonary metastasis of anal sac adenocarcinoma were identified on thoracic radiography. The ferret died at home on day 71 after the first admission.     

Pulmonary adenocarcinoma with osteoblastic bone metastases in a cat

A 12-year-old male cat with depression and dyspnoea was presented for investigation. Radiography and computed tomography revealed hydrothorax and solid masses involving the sternum, ribs and thoracic vertebrae. The cat died two days after first presentation, and postmortem examination revealed lung masses and proliferative bony lesions. Histologically, a neoplastic proliferation of epithelial cells was seen in the lungs, with a large amount of collagen and deposits of cholesterin. The bone lesions were also composed of neoplastic epithelial cells and abundant calcified osteoid, without atypia. A diagnosis of pulmonary adenocarcinoma with osteoblastic bone metastases was made. This is the first reported case of osteoblastic metastases in the cat.     

Use of computed tomography in the diseased feline thorax

Computed tomography (CT) scanning of the thorax is gaining more attention in veterinary medicine as therapeutic possibilities increase. Plain and contrast-enhanced CT images of the thorax of five referred cats with signs of respiratory disease were evaluated using soft tissue (pleural) and lung windows. The common CT pattern in all cats was involvement of the lung lobes, either as a homogeneous or heterogeneous single lobe hyperdensity. It involved the main bronchus, invaded the cranial or caudal mediastinum, and crossed the border to the opposite lung. Right lung atelectasis and mediastinal shift caused left lung overinflation. Bronchial lymph node enlargement was found unilaterally or bilaterally. CT-guided percutaneous fine needle aspiration biopsy of the lobar lung lesion was performed in four cats; in three cases it revealed carcinoma and in one inflammation, although the cat with suspected inflammation was subsequently found to have a carcinoma on lung lobectomy. Histopathology confirmed lung metastasis in one case and bronchial adenocarcinoma in four cases. A protocol for systematic examination of thoracic CT images is proposed.     

Diagnostic challenges: Equine thoracic neoplasia

The diagnosis of thoracic neoplasia in the horse can be difficult due to the nonspecific nature of the clinical signs and their overlap with other pulmonary diseases. Haematological and serum biochemical evaluation, thoracic ultrasonography, radiography, endoscopic examination, and, where appropriate, thoracocentesis and pleural fluid cytology may all be helpful in reaching a diagnosis. Granular cell tumours are the most frequently reported primary pulmonary tumours of horses. They occur as single or multiple masses adjacent to bronchi and bronchioles, and the mass typically extends into the airway, resulting in partial or complete occlusion of the lumen. Thymic tumours are classified as benign or metastatic, based on evidence of tissue invasiveness, even though they uniformly appear benign histologically. These tumours are derived from epithelial reticular cells of the thymus and are rare in horses. Other primary thoracic neoplasms originate from various pulmonary tissues and are primarily reported as single case reports: pulmonary and bronchial carcinoma and adenocarcinoma, bronchogenic squamous cell carcinoma, bronchial myxoma, pulmonary chondrosarcoma, pulmonary leiomyosarcoma and pleuropulmonary blastoma. Clinical signs of these primary pulmonary neoplasms are dependent on the tumour type and location, but commonly include chronic cough, weight loss, anorexia, fever and respiratory difficulty; ventral oedema, pleural effusion and epistaxis are also frequently observed. Mesothelioma is a rare primary pleural tumour arising from the mesothelium of the pleura, pericardium and peritoneum. The clinical presentation in horses includes weight loss, respiratory difficulty and large volume pleural effusion. The tumour appears ultrasonographically as multiple small nodules on a thick serosal surface and pleural biopsy is diagnostic. Lymphoma is the most common haematopoietic neoplasm in horses, which can present with 4 main manifestations of lesions: mediastinal, multicentric, alimentary and cutaneous. Common clinical features include chronic weight loss, lethargy, anorexia, subcutaneous oedema, lymphadenopathy, colic, bleeding tendency and diarrhoea. Coughing and laboured respiratory effort are often apparent in individuals suffering from mediastinal masses. In such instances, pleural effusion may result in severe pulmonary atelectasis and pulmonary function is significantly compromised. Haemangiosarcoma is the second most common metastatic thoracic neoplasm in horses. Disseminated haemangiosarcoma is aggressive and rapidly progressive. The clinical presentation often includes tachypnoea, pale or icteric mucous membranes, respiratory distress, epistaxis, and subcutaneous, cutaneous or intramuscular masses. Other tumour types that metastasise to the thoracic cavity include adenocarcinoma, squamous cell carcinoma, fibrosarcoma, metastatic melanoma, mastocytoma and undifferentiated sarcoma. The clinical features of these tumours are generally nonspecific and often relate more to the primary site of tumour formation.     

Comparison of thoracic radiographs and single breath-hold helical CT for detection of pulmonary nodules in dogs with metastatic neoplasia

Imaging studies in people indicate that x-ray computed tomography (CT) is a more sensitive technique than thoracic radiography for the detection of pulmonary metastasic neoplasia. Systematic studies comparing CT and thoracic radiographic techniques in veterinary patients have not been performed. The present retrospective study was designed to directly compare the efficacy of these 2 techniques in detecting pulmonary nodules in dogs. Eighteen dogs with histologically confirmed pulmonary metastatic neoplasia had contemporaneous thoracic radiographs and pulmonary CT scans compared. Quantitative analyses included estimation of pulmonary nodule size, number, and lobar distribution on thoracic radiographs and CT images. Only 9% of CT-detected pulmonary nodules were identified on thoracic radiographs (P < .003). The lower size threshold was approximately 1 mm to detect pulmonary nodules on CT images and 7-9 mm to reliably detect nodules on radiographs (P < .0001). Additionally, pulmonary nodules were detected in a significantly greater number of lung lobes using CT as compared with thoracic radiographs (P < .0001). These data indicate that CT is significantly more sensitive than thoracic radiography for detecting soft-tissue nodules in dogs. As such, thoracic CT should be considered in any patient with neoplasia that has potential for pulmonary metastasis to more reliably stage the disease, particularly when accurate characterization of the extent and distribution of pulmonary metastatic disease affects therapeutic planning.     

RADIOGRAPHIC ASSESSMENT OF PULMONARY FLUID CLEARANCE IN HEALTHY NEONATAL FOALS

We characterized the kinetics of postnatal equine lung using sequential thoracic radiography. The aim was to establish the earliest time when normal foals have clear, radiolucent lung fields, and to characterize the pattern of this clearance. Both right-to-left and left-to-right thoracic radiographs were acquired in lateral recumbency at peak inspiration within the first 30 min after birth and thereafter at 1, 2, 3, 4, 6, 8, 12, 24, 48, and 72 h. Radiographs were interpreted by three observers. The overall assessment of radiographic lung clearance was followed by the evaluation of individual lung quadrants to document changes in pulmonary radiographic patterns over time. We concluded that thoracic images in a healthy foal older than 4 h should be characterized by clear lungfields and that after this time distinctions between physiologic and pathologic conditions can be made. The ventral lung cleared first, presumably due to the greater flexibility of the thoracic wall in this anatomic region.     

Pasteurella haemolytica A1 and Bovine Respiratory Disease: Pathogenesis

The severe fibrinonecrotic pneumonia associated with pneumonic pasteurellosis usually results from colonization of the lower respiratory tract by Pasteurella haemolytica biotype A, serotype 1(A1). Despite recent research efforts, the authors lack a detailed understanding of the interactions and host response to P. haemolytica in the respiratory tract. The authors hypothesize that management and environmental stress factors or viral infection alters the upper respiratory tract (URT) epithelium allowing P. haemolytica to colonize the epithelium. Once the URT is colonized, large numbers of organisms enter the lung where they interact with alveolar macrophages. Endotoxin, released from the bacteria, crosses the alveolar wall where it activates pulmonary intravascular macrophages, endothelium, neutrophils, lymphocytes, platelets, complement, and Hageman factor leading to complex interactions of cells and mediators. It is the progression of this inflammatory response with neutrophil influx that is ultimately responsible for the pulmonary injury. Leukotoxin is a major virulence factor of P. haemolytica that allows it to survive by destroying phagocytic cells. At subcytolytic concentrations it may also enhance the inflammatory response by activating cells to produce mediators and release reactive oxygen metabolites and proteases.     

CARDIAC AND PULMONARY ARTERY MENSURATION IN FELINE HEARTWORM DISEASE

A retrospective study was undertaken to quantify thoracic radiographic changes in cats with heartworm diseases, ( Dirofilaria immitis ). Using a blinded study format, the cardiac silhouette, thoracic cavity and pulmonary arteries were measured from thoracic radiographs of 21 cats with feline heartworm disease and 30 cats without known cardiac or pulmonary vessel pathology. Measured data were normalized to the thoracic cavity or bony structures within the radiographic field of view. The measurements were compared between the two groups of cats using an unpaired, two-tailed Student's t -test, with a p value of < 0.05 being considered significant. Cats with feline heartworm disease had enlargement of the craniocaudal aspect of the cardiac silhouette and normalized cardiac:thoracic ratio (p < 0.05) on the lateral view. Also, there was significant enlargement of the central and peripheral caudal lobar pulmonary arteries and their normalized ratios (p < 0.05) in the heartworm infected cats as visualized on the ventrodorsal projection. Tortuosity of the pulmonary arteries was seen in three of the 21 infected cats. Eleven of the 21 cats with feline heartworm disease had pulmonary parenchymal changes. Based on the present study, central and peripheral pulmonary artery enlargement as viewed on the ventrodorsal radiograph was the single best radiographic indicator of feline heartworm disease.     

RADIATION PNEUMONITIS IN THREE DOGS

Radiation pneumonitis developed within the radiation treatment field in three dogs with soft tissue sarcomas located on or adjacent to the thoracic wall. Radiographic signs compatible with a diagnosis of radiation pneumonitis developed from one (n = 2 dogs) to two (n = 1 dog) months after completion of therapy. The initial radiographic sign was an alveolar infiltrate in all three dogs. At subsequent examinations at variable time periods after treatment, radiographic findings included: bronchiectasis (n = 3 dogs), alveolar infiltrate (n = 2 dogs), decreased lung volume (n = 2 dogs), and unstructured interstitial opacification (n = 1 dog). Necropsy examination of one dog at fourteen months after the completion of radiotherapy showed evidence of pulmonary fibrosis within the irradiated lung. Necropsy examination of the second dog did not show any evidence of radiation induced changes. It is possible that histopathologic examination did not include irradiated lung. No clinical signs that could be attributed to the radiation pneumonitis were observed in any dog. It appears that approximately 25% of the lung can be safely irradiated to high doses, if indicated, in order to deliver an adequate dose of radiation to a primary tumor site.     

Acute hemodynamic effects of hydralazine in dogs with chronic mitral regurgitation

The hemodynamic response to hydralazine administration was evaluated in 6 conscious small dogs with chronic mitral regurgitation. All dogs underwent invasive and noninvasive hemodynamic monitoring before and after hydralazine administration. Cardiac output and pulmonary capillary wedge pressure were measured with a Swan-Ganz thermodilution catheter. Systemic arterial blood pressure (AP) was measured directly by inserting a needle into the femoral artery. Standard M-mode echocardiograms and thoracic radiographs were obtained. Other hemodynamic variables were calculated. Base-line hemodynamic variables were altered severely in all dogs. Hydralazine decreased mean arterial blood pressure from 104 +/- 18 (mean +/- SD) to 78 +/- 12 mm of Hg (P less than 0.005), total systemic resistance index from 2,946 +/- 625 to 1,261 +/- 420 dynes-s-cm-5m2 (P less than 0.005), and pulmonary capillary wedge pressure from 40 +/- 5 to 26 +/- 3 mm of Hg, (P less than 0.005). Cardiac index increased from 2.92 +/- 0.72 to 5.36 +/- 1.67 L/min/m2 of body surface area (P less than 0.005). Mixed venous oxygen tension (PvO2) increased from 28.4 +/- 4.3 to 41.2 +/- 5.2 mm of Hg (P less than 0.001). Pulmonary edema resolved, as determined on thoracic radiographs. Mixed venous oxygen tension correlated well with the cardiac index (r = 0.92; P less than 0.001). It was concluded that hydralazine administration caused a small decrease in end diastolic diameter (4.8 +/- 0.9 to 4.5 +/- 0.8 cm, P less than 0.05) and end systolic diameter (2.6 +/- 0.8 to 2.3 +/- 0.7 cm, P less than 0.05). Fractional shortening and heart rate did not change.(ABSTRACT TRUNCATED AT 250 WORDS)     

Successful treatment of cryptococcal pneumonia in a pony mare

A 20-year-old Welsh Mountain Pony (212 kg) mare was initially presented for a chronic cough, fever, weight loss and low grade abdominal pain. She later developed dyspnoea, tachypnoea and exercise intolerance. The presence of multiple masses (up to 17 cm diameter) in the pulmonary parenchyma was established using lateral thoracic radiography and transthoracic ultrasonography. Encapsulated, budding yeasts were observed in smears made from transtracheal washings and needle aspirates of the pulmonary lesions. Cryptococcus gattii (synonym: Cryptococcus neoformans variety gattii; Cryptococcus bacillisporus) was cultured from the transtracheal washings and aspirates of the lung masses. The pony was successfully treated using daily intravenous infusions of amphotericin B (typically 0.5 mg/kg in 1 L 5% dextrose in water over 1 h, following premedication with 50 mg flunixin intravenously) over a 1 month period, until a cumulative dose of 3 g had been administered. Treatment was considered to be successful on the basis of progressive improvement in clinical signs, reduction in the size of pulmonary cryptococcomas, 48 kg weight gain and a reduction in the cryptococcal antigen titre from 4096 to 256, 1 year after cessation of treatment.     

Clinical use of echocardiography in the domestic cat

Echocardiograms were obtained from unanesthetized cats positioned in left lateral recumbency. Information regarding chamber wall thickness, lumen dimensions, valve motion, and indices of contractility was obtained. In three cases, echocardiographic manifestations typical of cardiac dilatation, cardiac hypertrophy, and pericardial effusion were recorded. Unlike thoracic radiographs, which portray pulmonary features as well as a cardiac silhouette, the echocardiogram provided an opportunity to measure each component comprising the cardiac silhouette--namely, the pericardial sac, cardiac musculature, and the cardiac chambers.