Presumptive primary intrathoracic mast cell tumours in two dogs.

BACKGROUND: Mast cell tumours are the most common cutaneous neoplasms in dogs. Other primary sites include visceral organs, such as the gastrointestinal tract, liver, or spleen, and the oral cavity. Frequent metastatic sites include the local lymph nodes, skin, spleen, liver and bone marrow. The thorax is rarely affected by metastatic disease and no such cases have been reported in dogs. Mast cell tumours are usually not considered as a differential diagnosis for lung and intrathoracic chest wall masses in dogs. Chest wall tumours can be primary tumours of the ribs and sternum, an invasion of adjacent tumours into the chest wall, and metastasis from distant tumours. CASES PRESENTATION: A German Shepherd dog presented with a history of persistent cough and a large mass involving the thoracic wall and a small round pulmonary mass. The dog had a history of mammary tumours that were surgically excised. Thoracoscopy revealed a thoracic wall mass involving the internal intercostal muscle and a small mass in the left cranial lung lobe. Cytology and histopathology of the intrathoracic mass confirmed the large mass as a mast cell tumour and the small mass as a carcinoma. Cytology of the sternal lymph nodes showed no involvement. The dog received toceranib for 3 months, which failed to alleviate persistent cough. Radiology indicated that the large mass had a partial response to toceranib. The dog was euthanasied. A Maltese dog presented with a history of chronic regurgitation and cough, and a large mass involving the left caudal lung lobe. Cytology and histopathology of mass confirmed a mast cell tumour. The dog received toceranib for 2 months. Radiology indicated that the large mass had no response to toceranib. The dog was euthanasied. Confirmation of lungs mast cell tumour and the absence of any other Mast cell tumour was achieved by postmortem examination. CONCLUSIONS: The cases discussed are two unusual presentations of intrathoracic mast cell tumours, in the absence of cutaneous mast cell tumours, in dogs.

Canine intrathoracic sarcoma with ultrastructural characteristics of human synovial sarcoma - case report.

BACKGROUND: Canine joint sarcomas, designated synovial sarcomas, are uncommon malignant mesenchymal neoplasms that occur in the large joints of the extremities of middle-aged, large-breed dogs. We report the diagnosis of an intrathoracic sarcoma with ultrastructural characteristics reminiscent of human synovial sarcoma in a dog. CASE PRESENTATION: A 7-year-old female spayed Tibetan terrier crossbred dog was presented for acute severe labored breathing and diagnosed with an intrathoracic neoplastic mass. The neoplasm resulted in the accumulation of substantial amounts of viscous pleural fluid that led to dyspnea. The neoplastic mass consisted of interweaving bundles of large pleomorphic mesenchymal cells, supported by an alcian blue positive myxomatous matrix. The neoplastic cells were immunohistochemically negative for cytokeratin and CD18. Transmission electron microscopy indicated that the neoplastic cells had desmosome junctions, short microvilli-like structures and ample amounts of rough endoplasmic reticulum resembling type B-like synoviocytes and synovial sarcoma as reported in people. Despite complete surgical excision of the neoplastic mass, clinical signs recurred after a month and led to the euthanasia of the dog. CONCLUSION: Currently, there are no immunohistochemical markers specific for synovial sarcoma. Canine neoplasms with transmission electron microscopy characteristics resembling type B-like synoviocytes should be considered similar to the human sarcomas that carry the specific translocations between chromosomes X and 18.

[Haemoabdomen and haemothorax in a cow with metastatic granulosa cell tumor]. / Hämoabdomen und Hämothorax bei einem Rind mit metastasierendem Granulosazelltumor.

This case report describes the clinical, ultrasonographic, pathological and histological findings in a two-year-old Swiss Braunvieh cow with granulosa cell tumor and metastases in the abdomen and thorax. The cow was ill and had tachycardia, coughing, increased breath sounds, positive reticular foreign body tests and a tense abdominal wall. Ultrasonography revealed a massive accumulation of hypoechoic fluid in the thorax and abdomen, and abdomino- and thoracocentesis yielded red fluid indicative of abdominal and thoracic haemorrhage. Because of a poor prognosis, the cow was euthanized and examined postmortem. Multiple nodular lesions were seen in the omentum, liver, spleen and lungs. The left ovary was grossly enlarged and nodular in appearance. Histological examination of the lesions revealed granulosa cell tumour of the left ovary and metastases in the omentum, liver, spleen and lungs.

Surgical approach and presence of preoperative pleural effusion impact thoracostomy tube usage in dogs and cats following thoracic surgery for suspected neoplasia.

OBJECTIVE: To assess factors associated with increased pleural fluid and air evacuation, longer duration of thoracostomy tube usage, and longer hospitalization in dogs and cats following surgery for thoracic neoplasms. ANIMALS: 62 dogs and 10 cats. METHODS: Medical records were reviewed for dogs and cats undergoing thoracic surgeries between August 1, 2019, and June 30, 2023, for resection of suspected neoplasia in which a thoracostomy tube was placed. Data collected included patient signalment, type of procedure performed, histologic diagnosis of the primary mass removed, volume of fluid and air evacuated from the thoracostomy tube, and time in hospital. RESULTS: Median sternotomy was associated with increased total fluid evacuation (median, 12.1 mL/kg; IQR, 15.4 mL/kg; P = .012), whereas rib resection was associated with increased total air evacuation (median, 2.1 mL/kg; IQR, 13.6 mL/kg; P = .06). The presence of preoperative pleural effusion was associated with higher total fluid evacuation (20.6 mL/kg; IQR, 32.1 mL/kg; P = .009), longer duration with a thoracostomy tube in place (42.5 hours; IQR, 41.9 hours; P = .027), and longer hospitalization period (61 hours; IQR, 52.8 hours; P = .025). Cats had a thoracostomy tube in place for a longer time compared to dogs (median, 42.6 hours; IQR, 23.5 hours; P = .043). CLINICAL RELEVANCE: Animals undergoing median sternotomy and rib resection may be expected to have higher fluid and air volumes, respectively, evacuated postoperatively. This often leads to an increased duration of thoracostomy tube usage and a longer period of hospitalization.

Intrathoracic lipoma in a cat.

A 10 yr old female cat presented for an acute onset of back arching, regurgitation, and open mouth breathing. Radiographs indicated the presence of a large intrathoracic mass. Computed tomography confirmed the presence of a large mass of fatty density in the dorso-caudal mediastinum. The mass was removed via right intercostal thoracotomy, and histopathology confirmed the mass as a lipoma. The cat was continuing to recover well as of 21 mo after surgery. This is the first reported case of an intrathoracic lipoma in a cat.

Pleomorphic liposarcoma of the intrathoracic cavity in a meerkat (Suricata suricatta).

Postmortem examination of a meerkat which had been captive for eight years in zoo, revealed multinodular white masses filling the thoracic cavity with systemic metastasis. Microscopically, the neoplastic cells were polygonal to spindle-shaped and had eosinophilic cytoplasm often with variable numbers of small lipid droplets. Immunohistochemically, the neoplastic cells were intensely positive for vimentin and occasionally weakly positive for S-100. Ultrastructurally, several lipid droplets without limiting membranes were observed in the cytoplasm. Based on the findings above, the tumor was diagnosed as a pleomorphic liposarcoma arising from the thoracic cavity. To date, neoplasms have seldom been reported in Herpestidae animals. To the authors' knowledge, this is the first reported case of liposarcoma in a meerkat.

Rhabdomyosarcoma with posterior paresis and megaesophagus in a Holstein heifer.

A 7-month-old Holstein heifer presented with posterior paresis and megaesophagus. At post mortem examination, a nodular tumor was found attached to the thoracic wall and the eighth to eleventh thoracic vertebrae, adjacent to the left posterior pulmonary lobe. The tumor was diagnosed as rhabdomyosarcoma by histology. This is a very rare case of spinal infiltration of rhabdomyosarcoma in cattle.

Thoracic omentalization for long-term management of neoplastic pleural effusion in a cat.

CASE DESCRIPTION: An 11-year-old neutered female domestic longhair cat was evaluated because of a 1-week history of progressive dyspnea, signs of depression, and loss of appetite. A histiocytic sarcoma had been excised from the mammary gland 6 weeks earlier. CLINICAL FINDINGS: Physical examination findings were consistent with pleural effusion, and thoracic and abdominal radiography and ultrasonography revealed pleural effusion, a thoracic mass involving the aorta and pulmonary artery, and a caudal abdominal mass that most likely represented enlarged iliac lymph nodes. Cytologic examination of the pleural fluid and fine-needle aspirates from the iliac and right popliteal lymph nodes revealed abundant cells with neoplastic characteristics of indeterminate origin. The clinical diagnosis was generalized malignant neoplasia. TREATMENT AND OUTCOME: Pleural drainage was necessary every 5 to 6 days. Exploratory thoracotomy and biopsy of the mass were recommended for better characterization of the thoracic disease. Simultaneously, palliative treatment by advancement of the omentum into the thorax was performed. A final diagnosis of disseminated histiocytic sarcoma was made, and treatment with doxorubicin was begun after surgery. During the 13 months after surgery, the cat was free from signs of respiratory tract disease and had normal activity levels with good exercise tolerance. Fifteen months after surgery, the cat's clinical condition worsened and the cat died. CLINICAL RELEVANCE: Findings suggested that thoracic omentalization may be considered for palliative treatment of cats with refractory neoplastic pleural effusion when frequent thoracocentesis is necessary and other treatments are not suitable.

Spontaneous rhabdomyosarcoma in a young Sprague-Dawley rat.

An eight-week-old male Sprague-Dawley (SD) rat showed signs of emaciation, and masses were found in the subcutis around the cervical and thoracic regions. At necropsy, a multilobular mass, 2.2 x 1.8 x 2.0 cm in size, had grown from the left neck into the thoracic cavity. On a cutting surface, masses were firm and whitish to tan, with necrotic and hemorrhagic plaques. Microscopically, masses were composed of multiple nodules of tumor cells that were incompletely encapsulated with fibrous connective tissue. The tumor cells exhibited varied forms, from spindle to globoid shapes with minimal to abundant eosinophilic cytoplasm, and appeared as large, multinucleated cells; many of the tumor cells were vacuolated. Histochemistry results revealed that tumor cells exhibited some cross-striation in the cytoplasm using PTAH staining. There were some multinuclear tumor cells with vacuoles located around the nuclei, and these vacuoles showed reddish staining by the periodic acid Schiff (PAS) method. Immunohistochemical staining also expressed intense granular cytoplasmic staining for desmin and myoglobin, with highly positive staining for PCNA, whereas alpha-smooth muscle actin (alpha-SMA) was negative. Based on the pathology results, a spontaneous rhabdomyosarcoma with pleomorphic type was diagnosed in a young SD rat.

Chemotherapy and radiotherapy for treatment of cutaneous lymphoma in a ground cuscus (Phalanger gymnotis).

A 15-year-old female ground cuscus (Phalanger gymnotis) was presented with an isolated ulcerated, nonhealing lesion on the lateral thorax. Histopathology and immunohistochemistry were diagnostic for cutaneous T-cell lymphoma with incomplete excision. Oral chemotherapy with CCNU (lomustine) resulted in clinical remission that lasted 255 days, with no appreciable toxicity. Tumor recurrence was treated with radiation therapy, which resulted in 120 additional days of clinical remission. Subsequently, the tumor developed at a distant site and the cuscus was humanely euthanized. A slight decrease in appetite early in disease progression was the only adverse effect noted throughout the treatment period. Oral, minimally invasive chemotherapy, and adjunct radiation therapy were viable treatment options for this ground cuscus and should be considered for treatment of neoplasia in other nontraditional species.

Multilobular tumour of bone of the thoracic wall in a cat.

Multilobular tumour of bone is a rare neoplasm of the skull in middle-aged, medium-to-large breed dogs even if a few cases have also been described in cats and one horse. The aim of the present paper is to show both the computed-tomography features and the pathological findings of the above neoplasm affecting the thoracic wall of a cat. To the best of the authors' knowledge, such anomalous tumour localisation has never been reported and imaged in feline medicine.

Pericardial lipoma in a geriatric dog with an incidentally discovered thoracic mass.

An intrathoracic mass was discovered as an incidental finding in a 14-year-old, spayed, female Rottweiler cross during evaluation of urinary incontinence. Computed tomography suggested a pericardial or pleural location and high adipose content of the mass. The mass was removed via lateral thoracotomy with partial pericardectomy and was diagnosed as a pericardial lipoma. The dog recovered well, and there was no evidence of recurrence approximately one year later. Adipose tumours of the heart and its associated structures are rare in dogs and have been associated with both successful and fatal outcomes.

Subcutaneous malignant mast cell tumor in a Japanese macaque (Macaca fuscata).

The histopathological, immunohistochemical, and ultrastructural morphologic characteristics of a tumor in the subcutaneous tissue of the chest of a 19-year-old female Japanese macaque were investigated. Consequently, the mass was diagnosed as a malignant mast cell tumor (MCT). Tumors were present in both mammary gland portions of the anterior thorax. Both tumors showed the same histopathological findings. The tumor tissue was defined by the presence of delicate connective tissue, and the tumor cells grew in a cord-like or cobblestone pattern. The tumor cell cytoplasm was very clear. The nuclei were relatively uniform and the cells showed a low nucleus-cytoplasm ratio. The cytoplasmic granules stained blue with Alcian blue and eosinophils had infiltrated into the tumor tissue. Furthermore, immunohistochemical analysis revealed that the tumor cell membrane was positive for the anti-c-kit antibody. In ultrastructural morphologic analyses, all tumor cells showed a rich cytoplasm and, occasionally, granules wrapped in a limiting membrane of high electron density. The tumor cells had metastasized to the axillary lymph nodes, the kidney, and the peritoneum. Based on these results, the mass was diagnosed as a malignant MCT originating from the subcutaneous tissue of the chest. Since cases of MCTs in macaques are very rare, this report presents important new knowledge of neoplastic lesions in this species.

Neoplastic pleural effusion and intrathoracic metastasis of a scapular osteosarcoma in a dog: a multidisciplinary integrated diagnostic approach.

A 10-year-old, female spayed mixed-breed or cross-bred dog was referred to the Small Animal Teaching Hospital of the University of Liverpool due to tachypnea, dyspnea, and pleural effusion not responding to diuretics and antibiotics. The chest was drained and cytology of the pleural fluid was consistent with a modified transudate with presence of atypical cells initially attributed to mesothelial hyperplasia and dysplasia. Computed tomography detected, in addition to the bilateral pleural effusion, diffuse pleural thickening, multiple pleural and pulmonary nodules, and a mineralized and lytic mass in the left scapula. Imaging findings were suggestive of a primary bone tumor with intrathoracic metastasis. Cytology of the left scapular and pleural masses revealed a malignant neoplasm highly suggestive of osteosarcoma. The diagnosis was confirmed by demonstration of a positive cytochemical reaction for alkaline phosphatase on prestained cytology slides. This finding prompted review of the initial interpretation of the pleural effusion cytology. The presence of neoplastic osteoblasts in the thoracic fluid was identified by a combination of cytochemistry, cell pellet immunohistochemistry, and transmission electron microscopy findings. In this report, a multidisciplinary integrated diagnostic approach was used to diagnose and confirm a neoplastic pleural effusion due to osteosarcoma metastasis in a dog.

Factors influencing the short-term outcome following thoracic surgery in 98 dogs.

OBJECTIVES: To evaluate the factors influencing the short-term (<14 days) outcome of thoracic surgery in dogs. METHODS: A retrospective review of 98 dogs undergoing thoracotomy over a five-year period was undertaken. RESULTS: A pre-operative diagnosis was achieved in 69 per cent of cases. Intrathoraic neoplasia had the lowest pre-operative diagnosis rate (5.5 per cent). Mortality rates of 21 per cent were recorded and were significantly higher for intrathoracic neoplasia (50 per cent) and significantly lower for persistent ductus arteriosus (7.4 per cent) and vascular ring anomaly (0 per cent). Median sternotomy was the preferred approach for pyothorax (85 per cent) and penetrating thoracic injuries (66 per cent). Intercostal thoracotomy was the preferred approach for all other diseases. Postoperative complications occurred in 39 per cent of cases. Wound complications were more common for pyothorax (45 per cent) and following median sternotomy (71 per cent). Thoracic drains were placed in 77 per cent of cases and complications were recorded in 23 per cent. Pyothorax and chylothorax had thoracic drains maintained for significantly longer periods of time. Longer thoracic drain duration was correlated significantly with increased complication rates. CLINICAL SIGNIFICANCE: The short-term outcome following thoracic surgery is influenced by diagnosis. The thoracic approach is determined by intrathoracic disease, but may influence outcome by affecting the incidence of postoperative wound complications. The risk of thoracic drain complications increases with drain duration, which is influenced by the underlying disease. Drains should be maintained for the minimal amount of time possible.

Matrix "blues": clue to a cranial thoracic mass in a dog.

A 5-year-old, intact male Italian Spinone dog was presented for progressive, severe dyspnea and coughing. Thoracic radiographs revealed a large mass in the right cranial thorax. Fine needle aspiration of the mass yielded a highly cellular sample containing dense clumps of oval to spindle-shaped mesenchymal cells with distinct intracytoplasmic vacuolation, consistent with lipoblasts and lipocytes. Cell clusters were associated with abundant eosinophilic matrix, which was identified as mucin, based on Alcian blue staining. At exploratory thoracotomy, the mass was found to be nonresectable, and the dog was euthanized. Histologic sections of the multilobular mass had discrete regions of variable cellular differentiation, including highly cellular areas of pleomorphic cells, areas of spindle cells and lipoblasts in a myxoid background, and areas of well-differentiated lipogenic cells. The histologic diagnosis was myxoid liposarcoma. The thoracic cavity is a rare site for liposarcoma in the dog. The cytologic features of lipoblasts together with a mucopolysaccharide matrix were useful for distinguishing the myxoid variant of liposarcoma from other forms of liposarcoma and myxoid sarcomas.

Sudden death due to thoracic lymphoma in a standardbred racing horse.

During training, a 6-year-old standardbred gelding collapsed, exhibiting severe epistaxis and agonal breathing and was euthanized. The horse had a recent history of poor performance, lethargy, and unilateral eyelid swelling with serous ocular discharge. Postmortem and histopathologic examination findings revealed thoracic lymphosarcoma and concurrent exercise-induced pulmonary hemorrhage.

Computed tomography and magnetic resonance imaging of thoracic chordoma in a Bengal tiger (Panthera tigris tigris).

A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.

Imaging of spontaneous canine tumours with ammonia and L-glutamine labeled with N-13.

Ammonia and 6-glutamine, labeled with N-13, were tested as imaging agents for a variety of spontaneous canine tumors. The imaging capabilities of these compounds were compared with each other, with other scanning agents, and with radiologic and pathologic procedures. Good agreement between positive gamma images and postmortem findings occurred in 11 of 15 cases with [13N] ammonia as the localizing agent. Eight of the nine scans using [13N] glutamine as the imaging agent showed positive correlation with postmortem findings. In cases where both ammonia and glutamine were used to image the same lesion, no qualitative differences in tumor uptake were found between the two.

Use of immunohistochemical marker calretinin in the diagnosis of a diffuse malignant metastatic mesothelioma in an equine.

Mesotheliomas are rarely reported in animal species. In this report, the occurrence of a diffuse, metastatic mesothelioma in a 6-year-old gray Arabian mare is described. The mare was presented on clinical examination with ascites, bilateral pleural effusion, and pleural roughening. Necropsy revealed abundant fluid in the abdominal and thoracic cavities. The surface of all organs was thick and fibrosed with multiple raised nodules and hemorrhages. Histology was characteristic of a generalized, biphasic mesothelioma with vascular and lymph nodes metastases. It is believed that the primary tumor developed in the pericardium and spread through lymphatics. In this report, calretinin was used as an immunohistochemical marker in the diagnosis of mesothelioma in an equine species for the first time.