Presumed mediastinal cysts have a low prevalence in canine thoracic computed tomographic studies

Mediastinal cysts (MCs) are rare lesions that can arise from embryonic remnants of various mediastinal structures. MCs usually are incidental findings in dogs and cats; however, they can reach a mass-like appearance. The description of MCs on CT in dogs is limited. This retrospective, single-center, descriptive, prevalence study aimed to determine the prevalence of presumed mediastinal cysts (PMCs) in dogs and assess their CT characteristics. Dogs that underwent a thoracic CT scan from January 2019 to August 2021 were included. CT images were evaluated for the presence of PMCs by two diagnostic imaging interns, two last year diagnostic imaging residents, and a board-certified veterinary radiologist. Number, location, margins, shape, volume, size, mass effect, and attenuation values of PMCs were assessed. A total of 866 CT scans were reviewed, and 49 PMCs were identified. The prevalence of PMCs in dogs was 5.66%. English Bulldog and mixed-breed dogs were subjectively overrepresented; however, the possibility of population bias could not be excluded. PMCs were subjectively more frequently observed in male dogs. The PMCs were predominantly round, small, solitary fluid-filled findings localized in the cranioventral mediastinum, with well-defined margins, homogeneous attenuation, and no contrast enhancement. The median attenuation value was 6.32 HU (range: -20.16 to 23.45 HU) precontrast and 7.58 HU (range: -2.45 to 20.79 HU) postcontrast, and the median volume was 1.19 cm3 (range: 0.02-45.32 cm3). Although the prevalence of PMCs was low in our sample population, findings supported prioritizing a differential diagnosis of incidental PMC for dogs with the above imaging characteristics.

Anomalous origin of the right subclavian artery in a Neotropical otter (Lontra longicaudis, Olfers-1818)

The Neotropical otter (Lontra longicaudis) is a mustelid distributed geographically from Mexico to Argentina. Anomalous origins of the aortic arch branches are rarely reported in wild carnivorans. Therefore, this study aimed to report the anomalous branching of the aortic arch in one formaldehyde-fixed specimen of L. longicaudis. The aortic arch provided three branches: the bicarotid trunk and the left and right subclavian arteries. The latter passed dorsally to the esophagus toward the right side without a mark of compression at the esophagus. This is the first report of an anomalous origin of the right subclavian artery in L. longicaudis.

Primary ectopic meningioma in the thoracic cavity: A rare case report and review of the literature

Background

Meningioma is a common type of intracranial tumor in adults. It rarely arises in the chest, with only a few case reports in the English literature. Here, we report the case of a patient with a primary ectopic meningioma (PEM) located in the thoracic cavity.

Case presentation

A 55-year-old woman presented with exercise-induced asthma, chest tightness, intermittent dry cough and fatigue for several months. Computed tomography revealed the presence of a huge mass in the thoracic cavity, with no connection to the spinal canal. Lung cancer and mesothelioma were suspected, and surgery was performed. Grossly, the mass was a grayish-white solid 9.5 cm × 8.4 cm × 5.3 cm in size. The microscopic morphology of the lesion was consistent with that of typical central nervous system meningioma. The pathological subtype was transitional meningioma. The tumor cells were arranged in a fascicular, whorled, storiform and meningithelial pattern, with occasional intranuclear pseudo-inclusions and psammoma bodies. In focal areas tumor cells were considerably dense, and the cells were round or irregular in shape, with less cytoplasm, uniform nuclear chromatin, and visible nucleoli and mitoses (2/10 HPF). By immunohistochemistry, the neoplastic cells showed strong and diffuse staining with vimentin, epithelial membrane antigen and SSTR2 with variable expression of PR, ALK and S100 protein. However, the cells were negative for GFAP, SOX-10, inhibin, CD34, STAT6, smooth muscle actin, desmin, CKpan, D2-40, WT-1, CK5/6 and CD45. The highest proliferation index by Ki-67 was 15%. The abnormal expression of ALK led to the initial misdiagnosis of an inflammatory myofibroblastic tumor. After 12 months of follow-up, no disease progression was observed.

Conclusion

The presence of primary ectopic meningiomas in the thoracic cavity is extremely rare, and this tumor is easily misdiagnosed clinically. Imaging is suggested to determine the location and possible differential diagnosis, while the final diagnosis should be via pathological examination. Immunohistochemistry is crucial for disease diagnosis. Owing to our limited knowledge of PEM, its pathogenesis and tissue of origin remain unclear. Clinicians should pay close attention to such potential patients. The present case report may provide insights into the diagnosis and therapy of patients with this tumor.

Spontaneous Tension Hemothorax in a Patient with Asbestosis

CASE PRESENTATION

A 75-year-old man with a history of asbestosis presented to the emergency department with sudden-onset dyspnea and hemoptysis, triggered by coughing. The patient was hemodynamically unstable and in respiratory distress. Computed tomography revealed a massive hemothorax on the left side and compression of the descending thoracic aorta. He underwent emergency surgical exploration after decompression by chest tube insertion. The hemothorax was caused by tears in the pleural adhesions due to asbestosis and induced by coughing.

DISCUSSION

Spontaneous hemothorax is a rare subtype of hemothorax. There have been only a few case reports of spontaneous tension hemothorax. In addition to its typical findings, compression of the thoracic descending aorta was observed in our patient. We hypothesize that severely diminished pulmonary compliance contributed to the extremely high intrathoracic pressure, which led to this unusual finding.

Reinterventions after damage control surgery

Damage control has well-defined steps. However, there are still controversies regarding whom, when, and how re-interventions should be performed. This article summarizes the Trauma and Emergency Surgery Group (CTE) Cali-Colombia recommendations about the specific situations concerning second interventions of patients undergoing damage control surgery. We suggest packing as the preferred bleeding control strategy, followed by unpacking within the next 48-72 hours. In addition, a deferred anastomosis is recommended for correction of intestinal lesions, and patients treated with vascular shunts should be re-intervened within 24 hours for definitive management. Furthermore, abdominal or thoracic wall closure should be attempted within eight days. These strategies aim to decrease complications, morbidity, and mortality.

Malignant peripheral nerve sheath tumor of the thorax: Unusual location of a rare tumor

Malignant peripheral nerve sheath tumor (MPNST) is a rare variety as sporadic tumor but more common when associated with neurofibromatosis, and its usual site of origin lies in the extremities. MPNST of thoracic cavity is a rare site of origin with only anecdotal reports in literature. Progression to a large size without distant metastases is even rarer owing to its high metastatic potential. We present a case of thoracic MPNST highlighting its rarity and the treatment options available to provide a best possible outcome.

Laparoscopic repair of a peritoneopericardial diaphragmatic hernia after a convergent procedure for the treatment of atrial fibrillation

Peritoneopericardial diaphragmatic hernia is a rare entity involving herniation of abdominal viscera through the diaphragm into the pericardial sac. It is most often seen after blunt abdominal trauma, but can occur following any trans-diaphragmatic intervention. We report on a 56-year-old female with peritoneopericardial diaphragmatic hernia secondary to a convergent procedure for the treatment of atrial fibrillation, who underwent a laparoscopic repair. An anterior abdominal wall laparoscopic approach was employed. Transverse colon and greater omentum were within the hernia sac. The defect measuring 3 cm × 3 cm was repaired using a composite hernia mesh. The total operative time was 78 minutes. No intra-operative and no post-operative complications were observed. Patient remained asymptomatic at a 6-month follow-up. Laparoscopic mesh repair of peritoneopericardial diaphragmatic hernia is safe, feasible and is the procedure of choice for treating these complex hernias.

Comparison of acute phase protein and hemodynamic variables in dogs undergoing video-assisted thoracoscopic vs. open pneumonectomy

It has been demonstrated that video-assisted thoracoscopic surgery (VATS) is feasible and safe in humans and animal models. The aim of the present study was to compare the surgical outcome using VATS with that of the standard transthoracic approach for pneumonectomy in dogs, to determine the acute-phase reaction in VATS pneumonectomy, and to analyze the difference between VATS and the standard transthoracic approach. A total of 14 dogs were divided into two groups (n=7); one group underwent VATS and the other group underwent a transthoracic pneumonectomy. Pre-, intra- and post-operative physiologic parameters were monitored, in addition to the blood cell count and serum acute-phase protein (APP) concentrations. The APP and hemodynamic changes between the two approaches were analyzed. Mean surgical time in the VATS group (176.7 min) was significantly longer compared with the open group (132.4 min). All APP concentrations were significantly increased at day 1 postoperation and gradually decreased to preoperative concentrations. The serum concentration of C-reactive protein on day 3 and the white blood cell count on day 1 were significantly higher following surgery in the open group compared with the VATS group (P<0.05). No differences were observed in the physiological parameters between the two groups. Although VATS took longer, animals experienced smaller incision and less stress. Therefore, the VATS approach was satisfactory for total pneumonectomy.

Fluence Rate Differences in Photodynamic Therapy Efficacy and Activation of Epidermal Growth Factor Receptor after Treatment of the Tumor-Involved Murine Thoracic Cavity

Photodynamic therapy (PDT) of the thoracic cavity can be performed in conjunction with surgery to treat cancers of the lung and its pleura. However, illumination of the cavity results in tissue exposure to a broad range of fluence rates. In a murine model of intrathoracic PDT, we studied the efficacy of 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH; Photochlor^®)-mediated PDT in reducing the burden of non-small cell lung cancer for treatments performed at different incident fluence rates (75 versus 150 mW/cm). To better understand a role for growth factor signaling in disease progression after intrathoracic PDT, the expression and activation of epidermal growth factor receptor (EGFR) was evaluated in areas of post-treatment proliferation. The low fluence rate of 75 mW/cm produced the largest reductions in tumor burden. Bioluminescent imaging and histological staining for cell proliferation (anti-Ki-67) identified areas of disease progression at both fluence rates after PDT. However, increased EGFR activation in proliferative areas was detected only after treatment at the higher fluence rate of 150 mW/cm. These data suggest that fluence rate may affect the activation of survival factors, such as EGFR, and weaker activation at lower fluence rate could contribute to a smaller tumor burden after PDT at 75 mW/cm.

[Spontaneous pulmonary hernia: report of a case]

Pulmonary hernia is a protrusion of lung tissue through a defect in the chest wall. Its origin can be congenital or acquired; spontaneous presentation is the least frequent. We report a case of spontaneous intercostal pulmonary hernia with a brief description of the disease. In this case, the patient developed a hematoma in the left hemithorax associated to pain at the base of the left hemithorax after a Valsalva's maneuver. The images obtained by thoracic CT scan revealed the existence of a left intercostal hernia. After radiological diagnosis, surgical treatment of the defect was performed with good results.

Intrathoracic displacement of the humeral head in a trauma patient

Fracture and intrathoracic displacement of the humeral head is the result of severe high energy trauma and are extremely rare. Because of the exceedingly limited number of cases, appropriate treatment modality remains unclear. Hitherto, we describe a unique case of thoracic aorta injury caused by fragmented humeral head. Purposeful medical examination and fast locating of the humeral head fragment are crucial for the selection of appropriate treatment modality. Early aggressive intervention, e.g., emergency thoracoscopy exploring, can be performed to treat potential thoracic complications.

Mixed Type of Malignant Mesothelioma in an Aged Male ICR Mouse

Multiple whitish nodules in the thoracic cavity at the site of the thymus were observed in a 101-week-old male ICR mouse. In a histopathological examination, the neoplastic cells were predominantly fusiform in shape and proliferated in sarcomatoid growth patterns. Some neoplastic cells showed epithelial growth patterns, such as the ductal structures. Mitotic figures were frequently seen, and small necrotic foci and invasion to adjacent thoracic organs were noted. In Alcian blue staining, bluish materials were observed between fusiform-shaped cells and in some of the lumens of the ductal structures. In immunohistochemistry, both fusiform-shaped and ductal structure-forming cells were positive for vimentin and weakly positive to positive for cytokeratin. Based on the aforementioned findings, the thoracic nodules were diagnosed as a mixed type of malignant mesothelioma. This case was thought to be rare because of the very low occurrence of spontaneous mesothelioma in mice.

Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma

Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers.

Intrathoracic malignant peripheral nerve sheath tumor in von Recklinghausen's disease

Malignant peripheral nerve sheath tumor (MPNST) is defined as any malignant tumor arising from or differentiating toward the cells of the peripheral nerve sheath. MPNST accounts for about 5-10% of all soft tissue tumors and is often associated with neurofibromatosis type I (NF-1, von Recklinghausen's disease). It is one of the malignant tumors associated with von Recklinghausen's disease. Its common site is the lower and upper extremities, trunk, head and neck. But intrathoracic manifestations are very rare. We report a case of a 40 year-old man with multiple neurofibromatosis who was presented with an intrathoracic malignant peripheral nerve sheath tumor.