Diagnostic imaging and histopathologic features of rounded atelectasis in four cats and one dog: A descriptive case series study.

In humans, rounded atelectasis is defined as focal lung collapse that radiologically appears as a round mass-like lesion in the periphery of the lung. In general, human patients with rounded atelectasis have a history of pleural effusion and abnormal pleura and characteristic CT findings help to distinguish rounded atelectasis from pulmonary neoplasia without the need for invasive surgical biopsy. This retrospective multi-center case series describes rounded atelectasis in four cats and one dog. Chylothorax was seen in four patients and an eosinophilic and lymphoplasmacytic effusion was seen in one patient. All patients had solitary or multifocal subpleural pulmonary masses (26 masses total in 5 patients) with diffuse, multifocal, or focal visceral and parietal pleural thickening. All the masses but one were broad-based towards the visceral pleura. Masses were most common in the ventral or lateral aspect of the lungs. Indistinctness at the hilar aspect of the lesion was seen in all masses; a "comet tail" sign was seen in 14 of 26 masses. On postcontrast images, the lesions were homogeneously enhanced in 24 of 26 masses and heterogeneous in two of 26 masses. Other findings include ground glass opacities (n = 5), parenchymal bands (n = 4), mild to moderate lymphadenopathy (n = 4), and compensatory hyperinflation of the lung lobes not affected by atelectasis (n = 2). Histopathology of four cases revealed atelectasis with fixed pleural folds, chronic pleuritis, and mild to moderate pleural fibrosis. Awareness of rounded atelectasis in veterinary species will enable inclusion of a benign etiology into the differential diagnosis for subpleural masses in cases with pleural abnormalities.

Canine and Feline Exudative Pleural Diseases.

Exudative pleural diseases are a common cause of respiratory distress and systemic illness in dogs and cats. This article covers the pathophysiology, development, and classification of exudative pleural effusions. The most current diagnostic strategies, causes, imaging findings, and medical or surgical treatment options for select diseases are reviewed in detail.

Computed tomographic features of pneumothorax secondary to a bronchopleural fistula in two dogs.

A bronchopleural fistula (BPF) can lead to continuous pneumothorax and is rarely reported clinically in dogs. This report describes computed tomographic (CT) findings in two dogs with BPFs and subsequent continuous pneumothoraces that necessitated thoracotomy. Both dogs had a peripheral BPF in the right caudal lung lobe. The fistula in one dog was secondary to a previous foreign body migration, and the fistula in the other was thought to be secondary to dirofilariasis. On both CT examinations, a dilated subsegmental bronchus was seen communicating with the pleural space at the center of a focal, concave region of parenchymal consolidation. Multiplanar reformatting aided in identification and characterization of the BPF. The pneumothoraces resolved after right caudal lobectomy in both dogs. CT has the potential to identify BPFs, such as secondary to foreign body migration or dirofilariasis.

Mediastinectomy for management of chronic pyogranulomatous pleural disease in dogs.

The medical records of 12 dogs with chronic pyogranulomatous pleural disease unresponsive to medical management were reviewed retrospectively. Resection of the mediastinal pleura (mediastinectomy) was performed through a median sternotomy to remove all diseased and surgically accessible mediastinal pleural tissue. Dogs were re-examined two weeks postoperatively, and long-term outcome was evaluated by contacting owners by phone. Twelve dogs underwent mediastinectomy; additional surgeries included subtotal pericardiectomy (8), lung lobectomy (4) and partial diaphragmatic resection (2). Histology of resected tissue consistently revealed neutrophilic, pyogranulomatous cellulitis/serositis. Foreign material was evident in the mediastinal tissue of five dogs and microorganisms were recovered from three dogs. Two dogs developed pneumothorax immediately postoperatively; one dog developed haemothorax one month postoperatively and was euthanased. Median follow-up time was eight months (range: 6-43 months); eleven dogs were alive and considered to be symptom-free by their owners. Mediastinectomy resulted in complete resolution of symptoms in most dogs (92 per cent) and was associated with a low incidence of major complications. The results of this study indicated that mediastinectomy results in favourable outcome for dogs with chronic pleural pyogranulomatous pleural disease unresponsive to medical management.

Exudative pleural diseases in small animals.

Exudative pleural diseases are a common cause of respiratory distress and systemic illness in dogs and cats. This article addresses the pathophysiology, development, and classification of exudative pleural effusions. The most current diagnostic strategies, causes, imaging findings, and medical or surgical treatment options for select diseases are reviewed in detail.

Pleuro-pulmonary endometriosis in baboons (Papio spp.): insights into pathogenesis.

BACKGROUND: Human pleuro-pulmonary endometriosis (PPE) is rare. Recently, we identified several cases of abdominal endometriosis in baboons that developed PPE. MATERIALS AND METHODS: Ten cases of PPE and four of intra-abdominal endometriosis (three simultaneous) were identified at necropsy in baboons (Papio spp.) found dead due to natural causes. The endometriotic lesions were evaluated using immunohistochemistry. RESULTS: The stromal (CD10+) and epithelial cells in intra-abdominal cases were estrogen and progesterone receptor (ER/PR) positive and thyroid transcription factor 1 (TTF-1) negative similar to that seen in humans. In contrast, the PPE cases displayed TTF-1-positive epithelium lining the cystic spaces, while the stroma was ER/PR positive similar to that in abdominal endometriosis. Both lymph nodes and spindle cell rests in lung interstitium contained ER/PR-positive stromal cells. CONCLUSIONS: The lung lesions were different from the abdominal lesions in having a TTF-1-positive lining epithelium. The deep pulmonary interstitial and lymph node endometrial stromal rests probably arrive via lymphatic route. The endometrial stroma is the driving force in PPE upon which the lung-specific epithelium condenses and may require a novel approach to therapy.

Relationship between paradoxical breathing and pleural diseases in dyspneic dogs and cats: 389 cases (2001-2009).

OBJECTIVE: To determine the strength of the relationship between paradoxical breathing (PB) and spontaneous pleural diseases in dyspneic dogs and cats. DESIGN: Cross-sectional study. ANIMALS: Dogs (n = 195) and cats (194) with a recorded diagnosis of dyspnea examined at the National Veterinary Schools of Alfort and Toulouse (France) between January 2001 and October 2009. PROCEDURES: Dogs and cats were divided into 2 groups according to the presence or absence of PB. Stratified analysis by species was performed. Signalment of affected animals and occurrence of PB were recorded. The relationship between PB and pleural diseases among dyspneic dogs and cats was analyzed. RESULTS: A strong relationship between PB and pleural diseases was highlighted in multivariate analysis (dogs, OR = 12.6 and 95% confidence interval = 4.6 to 31.2; cats, OR = 14.1 and 95% confidence interval = 6.0 to 33.5). Paradoxical breathing prevalence among dyspneic dogs and cats was 27% and 64%, respectively. Occurrence of pleural diseases in dyspneic animals with and without PB was 49% and 9% in dogs and 66% and 13% in cats, respectively. The sensitivity and specificity of PB as a predictor of pleural diseases were 0.67 and 0.83 in dyspneic dogs and 0.90 and 0.58 in dyspneic cats, respectively. The positive and negative predictive values of PB were 0.49 and 0.91 in dyspneic dogs and 0.66 and 0.87 in dyspneic cats, respectively. Age, sex, feline breeds, and canine morphotypes in patients with PB were not significantly different from those of other dyspneic animals. CONCLUSIONS AND CLINICAL RELEVANCE: PB was strongly associated with pleural diseases in dyspneic dogs and cats. The presence of this clinical sign should prompt small animal practitioners to implement appropriate emergency procedures and guide their diagnostic strategy.

Pleural endometriosis in an aged rhesus macaque (Macaca mulatta): a histopathologic and immunohistochemical study.

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity and is one of the most common reproductive abnormalities encountered in women as well as Old World primates. The majority of endometriosis cases in Old World primates occur within the abdominal cavity, with spread to extraabdominal sites considered to be a rare event. A 19-year-old multiparous female rhesus macaque (Macaca mulatta) presented to necropsy for difficulty breathing and weight loss. Grossly, the animal had marked abdominal endometriosis and severe hemoabdomen and hemothorax, the latter of which was accompanied by marked pleural fibrosis. Histologic examination confirmed the abdominal endometriosis and also revealed numerous uterine glands and stroma embedded within the pleural fibrosis. Rafts of endometrial tissue were present within pulmonary lymphatics and the tracheobronchial lymph nodes. Immunohistochemically, all ectopic endometrial tissue had varying degrees of positive immunoreactivity to cytokeratin, vimentin, progesterone and estrogen receptors, and calretinin but was negative for desmin and carcinoembryonic antigen. Pleural endometriosis is an extremely rare manifestation of endometriosis in nonhuman primates. This case report emphasizes lymphatic spread as a likely mechanism for extrauterine endometriosis.

CT features of pleural masses and nodules.

Pleural space masses and nodules are rarely described on computed tomography (CT) in veterinary medicine and have only been described in patients with neoplasia. Our purpose was to describe the CT findings and diagnoses in seven patients with pleural masses and nodules. Two patients had broad-based, plaque-like pleural masses, both of which were due to neoplasia (primary pleural carcinoma, metastatic thymoma). Two patients had well-defined pleural nodules and nodular pleural thickening, one of which had mesothelial hypertrophy, and another of which had metastatic hemangiosarcoma. Three patients had ill-defined pleural nodules to nodular pleural thickening, one of which had metastatic pulmonary carcinoma, while the other two had bacterial infection with mesothelial proliferation (n = 2), fibrinous pleuritis (n = 1), and severe mediastinal pleuritis/mediastinitis (n = 2). Five of the seven patients had focal, multifocal or diffuse smooth, and/or irregular pleural thickening. Five of seven patients had pleural effusion, and postcontrast CT was useful in several patients for delineating the pleural lesions from the effusion. All patients except one had additional lesions identified on CT besides those in the pleural space. CT is useful in identifying and characterizing pleural space lesions and could be used to guide further diagnostic procedures such as thoracoscopy or exploratory thoracotomy. Both neoplastic and nonneoplastic diseases should be considered in the differential diagnoses for pleural space masses and nodules found on CT.

Biliothorax in a Siamese cat.

A 2-year-old male neutered cat presented for further investigation of biliothorax. The cat was initially treated for pyothorax, including bilateral chest drains for lavage of the pleural space. Five days later, the pleural effusion turned clear-yellow and had a bilirubin concentration of 427 µmol/l compared to the serum bilirubin concentration of 15 µmol/l. Exploratory surgery revealed a 2mm tear in the diaphragm, with a corresponding 2mm defect in the diaphragmatic surface of the gall bladder, creating a fistula between the gall bladder and the pleural cavity. The defects were repaired routinely and the cat made a full recovery. It was suspected that the tears had been created at the time of the thoracostomy tube placement. Biliothorax has not been described before in a cat, and appears to be a rare complication following thoracostomy tube placement.

Standing lateral thoracotomy in horses: indications, complications, and outcomes.

OBJECTIVE: To describe the indications for, complications arising from, and outcome of horses that had standing lateral thoracotomy for pleural or pericardial disease. STUDY DESIGN: Case series. ANIMALS: Horses (n=16). METHODS: Medical records (January 1990-December 2008) of sedated standing horses that had lateral thoracotomy were reviewed. Clinical and surgical findings, perioperative and short-term complications were recorded. Long-term (>6 months) outcome was determined through telephone conversations with owners and veterinarians. RESULTS: Mean (±SD) horse age was 6.6±5.3 years (range, 1-15 years). Thoracotomy was most commonly for treatment of recurrent or chronic pleural infection (94%). Anaerobic bacteria were frequently isolated from pleural effusion associated with pleuropneumonia (63%). Right lateral intercostal thoracotomy was performed in 13 horses (82%); intercostal muscle myectomy in 5 horses; and rib resection in 1. Perioperative complications were hemipneumothorax (2 horses) and short-term complications included cellulitis and abscessation of the thoracotomy site (6 horses). Fourteen (88%) horses survived to discharge and 46% of horses that survived returned to their previous level of athletic activity. CONCLUSIONS: Lateral thoracotomy is well tolerated by standing sedated horses with minimal perioperative and short-term complications. CLINICAL RELEVANCE: Standing lateral thoracotomy should be considered for the treatment of complicated pleuropneumonia in horses.

Evaluation of small-bore wire-guided chest drains for management of pleural space disease.

OBJECTIVES: To evaluate the efficacy and practicality of a small-bore wire-guided chest drain for management of pleural space disease in dogs and cats. MATERIALS AND METHODS: A 14 gauge chest drain was placed using a modified Seldinger technique in animals requiring ongoing management of pleural space disease. A questionnaire was used immediately after placement to collect data regarding the ease of placement, reliability and function of the drain. RESULTS: Twenty animals were enrolled in which 29 drains were placed. The most common pleural space disease encountered was pyothorax (10 of 20). Sixteen animals required sedation for placement, and 25 of 29 chest drains were inserted at the first attempt. Most drains were placed in less than 10 minutes. The median length of time of catheter use was three days. Few complications were noted during the insertion and throughout the use of the drains. Clinicians rated drain placement as "easy" in 27 of 29 times and the drain function as "good" in 24 of 29 times. CLINICAL SIGNIFICANCE: Small-bore wire-guided chest drains are an effective alternative to larger gauge drains. Only minor complications were seen during insertion of the chest drains, and their performance was deemed satisfactory in most cases.

Radiographic, computed tomographic, and ultrasonographic findings with migrating intrathoracic grass awns in dogs and cats.

The purpose of this study was to describe the clinical, radiographic, and computed tomographic findings in dogs and cats with migrating intrathoracic grass awns. Thirty-five dogs and five cats with visual confirmation of a grass awn following surgery, endoscopy or necropsy, and histology were assessed. The medical records and all diagnostic imaging studies were reviewed retrospectively. Labrador Retrievers or English Pointers < 5 years of age, with a history of coughing and hyperthermia, were the most common presentations. Seventeen animals had an inflammatory leukogram of which 14 had a left shift or toxic neutrophils. Radiographs were performed in 38 animals and computed tomography (CT) in 14. Thoracic radiographs were characterized by focal pulmonary interstitial to alveolar opacities (n = 26) that occurred most commonly in the caudal (n = 19) or accessory lobes (n = 8). Additional findings included pneumothorax (n = 9), pleural effusion (n = 8), and pleural thickening (n = 7). Pulmonary opacities identified on radiographs correlated to areas of pneumonia and foreign body location. CT findings included focal interstitial to alveolar pulmonary opacities (n = 12) most commonly in the right caudal lung lobe (n = 9), pleural thickening (n = 11), mildly enlarged intrathoracic lymph nodes (n = 10), soft tissue tracking (n = 7) with enhancing margins (n = 4), pneumothorax (n = 6), pleural effusion (n = 4), and foreign body visualization (n = 4). Histologic diagnoses included pulmonary and mediastinal granulomas or abscesses, bronchopneumonia, and pleuritis. Migrating intrathoracic grass awns should be considered as a differential diagnosis in coughing, febrile animals with focal interstitial to alveolar pulmonary opacities, pleural effusion, pleural thickening, and/or pneumothorax on radiographs or CT.

Thoracostomy tube placement in the dog.

Placement of a chest tube may be necessary for management of pleural space disease in mammals. This column describes two accepted techniques for thoracostomy tube placement in the dog.

Traumatic subarachnoid-pleural fistula in a dog.

Subarachnoid-pleural fistula is a rare occurrence in humans as a result of trauma or spinal surgery. Such fistulas commonly remain undiagnosed until sufficient cerebrospinal fluid accumulates in the pleural space to cause respiratory distress. We describe a subarachnoid-pleural fistula in a dog that occurred subsequent to blunt trauma sustained during a fall, with concurrent acute, traumatic intervertebral disc rupture. The extruded disc material penetrated the dura mater, allowing communication between the subarachnoid space and the extrapleural thoracic cavity. Radiographic, myelographic, and computed tomographic (CT) findings are reviewed. Abnormalities noted during myelography included an intradural-extramedullary lesion at T11-T12, with epidural leakage of contrast medium from the region of T12 extending cranially. In images from myelography and CT there was extravasation of contrast medium extending from the subarachnoid and epidural space into the extrapleural thoracic cavity.

Pneumonectomy: four case studies and a comparative review.

Pneumonectomy is the resection of all lung lobes in either the left or right lung field. The surgical technique and postoperative results of pneumonectomy for clinical disease have not been reported in companion animals. Pneumonectomy was performed in three dogs and one cat to treat pulmonary or pleural disease, and the postoperative outcome compared with the complications and results reported in the human literature. One dog died immediately postoperatively due to suspected respiratory insufficiency and the remaining three animals survived the perioperative period. Postoperative complications were reported in two animals. Cardiac complications occurred in the cat, with perioperative arrhythmias and progressive congestive heart failure. Gastrointestinal complications were diagnosed in one dog, with mediastinal shift and oesophageal dysfunction. Left- and right-sided pneumonectomy is feasible in companion animals, and the postoperative outcome and complications encountered in this series were similar to those reported in humans.

Abomasal ulceration and abomaso-pleural fistula in an 11-month-old beefmaster bull.

An 11-month-old, beefmaster bull presented with anorexia and signs of respiratory disease. Physical examination, thoracic ultrasonography and radiography, and pleural fluid analysis indicated pericarditis and septic neutrophilic pleuropneumonia. Postmortem findings were abomasal adherence to the diaphragm, a fibrotic fistulous tract connecting the abomasum and pleural cavity, granulomatous abomasitis, granulomatous pericarditis, and fibrinonecrotic pleuritis.

Mycobacterium marinum dermatitis and panniculitis with chronic pleuritis in a captive white whale (Delphinapterus leucas) with aortic rupture.

A 16-year-old female white whale, Delphinapterus leucas, died after nearly 18 months of chronic lymphopenia and pyogranulomatous dermatitis. Necropsy revealed rupture of the aorta with hemorrhage into the cranial mediastinum and between fascial planes of the ventral neck musculature. Multiple foci of ulcerative dermatitis and panniculitis were present across the thorax and abdomen and surrounded the genital folds. In addition, there was a chronic proliferative pleuritis with over 20 liters of histiocytic exudate in the thoracic cavity. Acid-fast bacteria consistent with Mycobacterium sp. were identified in sections of skin lesions and in cytospins of pleural exudate. Cultures of pleura and 1 skin lesion collected at necropsy yielded sparse growth of an acid-fast bacillus with colony characteristics and morphology consistent with Mycobacterium marinum. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis confirmed the presence of M. marinum DNA in samples of skin. This is the first documented occurrence of mycobacteriosis in a white whale and is a unique presentation of mycobacterial dermatitis and panniculitis with chronic pleuritis in a cetacean. The improved PCR-RFLP protocol utilized in this case unifies techniques from several protocols to differentiate between species of Nocardia and rapidly growing mycobacteria clinically relevant to aquatic animals.