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.

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.

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.

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.

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.

The efficacy of mechanical abrasion and talc slurry as methods of pleurodesis in normal dogs.

OBJECTIVE: To determine the efficacy of mechanical abrasion and talc slurry as methods for pleurodesis in normal dogs. STUDY DESIGN: Experimental study. ANIMALS OR SAMPLE POPULATION: Ten normal beagle dogs. METHODS: Group I dogs had mechanical abrasion (MA) of the pulmonary and costal pleurae performed in one hemithorax with a dry gauze sponge with a median sternotomy approach. Group II dogs had 100 mL of a 1 g talc slurry (TS) administered into one hemithorax through a tube thoracostomy. Administration of the TS was visualized by using video thoracoscopy. All dogs were evaluated at 2, 10, 20, and 30 days postoperatively by means of thoracic radiography and ultrasonographic thoracic wall measurement. The dogs were euthanatized 30 days postoperatively and a gross necropsy was performed. Hemithoraces were assigned a pleurodesis score (0-4) and an obliteration grade (0-6). Tissues were collected for histopathologic examination of pulmonary pleura, costal pleura, and pleural adhesions. Pulmonary and costal pleurae were graded for the degree of fibrosis (0-4). RESULTS: Obliteration grade and costal pleural fibrosis score were significantly higher for the treated sides in the MA dogs compared with the TS dogs. MA Dogs: Mechanical abrasion dogs had pleurodesis, obliteration, and pleural fibrosis scores that were greater on the treated side than the untreated side, however, the differences were not statistically significant. Only two MA dogs had firm adhesion of the pulmonary pleura to the costal pleura in portions of the cranial and middle lung lobes in the treated hemithorax. Thoracic wall surface area covered with adhesions was 15% and 21% in each of these two dogs. The median pulmonary pleural fibrosis score of all MA dogs for the treated hemithorax was 3 compared to 0 on the untreated side. TS Dogs: There was no statistical difference for pleurodesis scores and obliteration grades between the treated and untreated sides. No dogs showed evidence of pulmonary to costal pleural adhesions. Histopathology showed talc crossover into the untreated side in all five dogs. Median pulmonary fibrosis score of the treated hemithorax was 1 compared with 0 on the untreated side. CONCLUSIONS: Neither method of pleurodesis produced sufficient pleural adhesions to obliterate the pleural space. It is possible that the degree of pulmonary pleural fibrosis present in MA dogs may be sufficient to limit air leakage from pulmonary blebs and bullae resulting in successful treatment of spontaneous pneumothorax.

Ultrasonography of the thorax (excluding the heart).

Until recently, ultrasonography has had a subordinate role in the evaluation of the thorax in both small animals and humans, most likely due to the inability of sound to penetrate air-filled lung. When pathologic processes such as pleural effusion and lung consolidation provide an acoustic window to the thorax, however, thoracic ultrasonography becomes feasible. As this article illustrates, ultrasonography may be effectively employed in the diagnosis and management of various thoracic wall, pleural, mediastinal, pulmonary, and diaphragmatic diseases by providing valuable information not obtainable with routine radiography and enabling percutaneous aspiration or tissue core biopsy of lesions.

Combined hiatal and pleuroperitoneal hernia in a shar-pei.

This article presents an unusual combination of a type IV hiatal hernia and a pleuroperitoneal hernia in a young shar-pei. Pathogenesis, diagnosis, and treatment of both conditions are discussed. At surgery, close examination and palpation of the whole diaphragm are recommended to allow perioperative diagnosis of unexpected defects.

Pleural Mesocestoides and cardiac shock in an obese vervet monkey (Cercopithecus aethiops).

Only one case of infection by tetrathyridia larvae of the tapeworm genus Mesocestoides was detected in 416 necropsies of captive vervet monkeys (Cercopithecus aethiops). Two hundred nine larvae were distributed between both pleural cavities. Mass and size ranges of larvae were determined. A plasma cell reaction indicated a humoral immune response to parasite antigens, which may have contributed to acute, lethal cardiac shock. Coagulative myocytolysis was confirmed. The history of this case and associated circumstantial evidence and reports in the literature suggest that infection of primates by tetrathyridia probably occurs after capture rather than before.

Non-neoplastic surgical diseases of the lung and pleura.

Non-neoplastic diseases of the bronchi, pulmonary parenchyma, mediastinum, and pleura that are amenable to surgical management represent a wide range of unrelated etiopathogenic conditions that usually have a focal distribution. The author discusses the presurgical clinical, radiographic, and laboratory assessment and prognoses, and addresses therapeutic recommendations.

Pleural effusions and diseases of the pleura.

There are four factors that govern fluid movement to or from the pleural space: hydrostatic pressure, colloid osmotic pressure, filtration coefficient, and lymphatic function. When any of these factors are altered, fluid accumulates within the pleural space. Congestive heart failure, pancreatitis, neoplasia, hypoalbuminemia, and pulmonary thromboembolism can evoke pleural effusions by altering normal fluid transport mechanisms. This approach to pleural effusion helps to explain fluid accumulation. Chylothorax, hemothorax, and empyema are also covered in the article.