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.

Paratracheal air cysts are uncommon findings in the pediatric population.

PURPOSE: To determine the prevalence of paratracheal air cysts (PACs) in the pediatric population. METHODS: The chest CT images of pediatric patients between July 2007 and December 2014 were retrospectively reviewed for the presence and imaging findings of PACs. In addition, the association between PACs and the presence of bronchiectasis and air cystic pulmonary lesions were evaluated. RESULTS: Among a total of 819 pediatric patients (males = 527, 64.3 %), the overall prevalence of PACs was 1.3 % (n = 11; 1.7 % for infants, 0.4 % for children, and 1.9 % for adolescents). The presence of PACs showed no association with gender, age groups, or the presence of bronchiectasis and air cystic pulmonary lesions (P = 0.56, 0.88, 0.57 and 0.89, respectively). All PACs were located at the right side of the trachea at the thoracic inlet, and the median transverse diameter was 3.7 mm (range 2.0-7.0 mm); one PAC showed septation, and 27.3 % of PACs had communication with the trachea. CONCLUSION: In the pediatric population, the prevalence of PACs is 1.3 % as detected by chest CT. Knowledge of the prevalence and imaging findings of PAC would be useful to prevent confusion with pneumomediastinum or other cystic lesions in pediatric patients.

Branchial cleft anomalies and thymic cysts.

Branchial cleft anomalies are a common cause of congenital neck masses and can present as a cyst, sinus, or fistula. A comprehensive understanding of the embryologic basis of these anomalies aids in diagnosis and surgical excision. Fistulas tend to present at an earlier age than sinuses or cysts, with most lesions presenting as either a neck mass, draining sinus, or recurrent infections. The eventual management of each is complete surgical excision, which is curative. A history of recurrent preoperative infections leads to a higher rate of recurrence.

Paratracheal air cysts: prevalence and relevance to pulmonary emphysema and bronchiectasis using thoracic multidetector CT.

PURPOSE: We aimed to determine the prevalence of paratracheal air cysts (PTACs) and the relationship of PTACs with emphysema and bronchiectasis through retrospective analysis of multidetector computed tomography (MDCT) findings. METHODS: MDCT findings of 1027 consecutive patients who underwent routine thorax examination between January 2012 and January 2013 were evaluated retrospectively for the presence of PTACs. Localization of the PTACs, as well as their size, shape, and relationship with the trachea were examined. Presence of emphysema and bronchiectasis was recorded, and bronchiectasis severity index was calculated when present. We randomly selected 80 patients who had no visible PTACs as the control group. The findings of patients with and without PTACs were compared. RESULTS: PTACs were determined in 82 of 1027 patients (8%), in 8.8% of females and 7.3% of males. The presence of PTACs was determined to be independent of gender (P = 0.361). Eighty-one PTACs (98.8%) were located in the right side of the trachea and 56.1% had a tracheal connection. The presence of PTACs significantly correlated with the presence and severity of bronchiectasis (P = 0.001 and P = 0.005 respectively). There was no significant relationship between the presence of PTACs and the presence of emphysema on CT images (P = 0.125). CONCLUSION: The prevalence of PTACs was determined as 8% in this study. There was significant association between PTACs and bronchiectasis.

Case of combined paratracheal air cyst and accessory cardiac bronchus.

Paratracheal air cyst (PTAC) is rather frequently detected on thoracic multi-detector computed tomography (MDCT) in daily practice. Accessory cardiac bronchus (ACB) is a rare anomaly; however, the incidence rate is increasing with the use of recent high quality MDCT scanners. We report a case of combined PTAC and ACB that was incidentally detected by MDCT. Three dimensional CT images revealed anatomical details.

Paratracheal air cysts: prevalence and correlation with lung diseases using multi-detector CT.

INTRODUCTION: The purpose of this study was to determine the prevalence of paratracheal air cysts (PACs), their correlation with different lung diseases and their connection with the trachea by chest multi detector computed tomography (MDCT). METHODS: We retrospectively reviewed chest MDCT images of 8240 consecutive patients obtained from January 2010 to December 2011 with a 16-detector multi-detector CT scanner. PACs were assessed for prevalence, location, level, size and the presence of visible communication with the trachea. MDCT diagnoses were classified as normal, primary or metastatic malignancies, chronic obstructive pulmonary disease (COPD), pneumonia and other lung diseases. We randomly selected 330 patients who had no visible PACs for the control group. We evaluated the associations between patients' demographic findings (age and sex), MDCT findings of lung and the presence of PACs. The findings of the PACs and control groups were compared. Statistical analysis used chi-squared test and Mann-Whitney U-test for evaluation. RESULTS: PACs were presented in 301 patients (4%); 204 men and 97 women, ranging in age from 14 to 91 years (median = 57 years). There was no significant difference in the presence of PACs by age (P > 0.05). Male subjects showed higher prevalence (P = 0.005). Fifty PACs (16.6%) showed communication with the trachea or main bronchus. Although the relation between COPD and PACs was statistically significant (P < 0.001), there was no relation between primary or metastatic malignancies, pneumonia and other lung diseases and PACs. CONCLUSION: PACs are common in MDCT and should not be misdiagnosed as pneumomediastinum. It should be kept in mind that PACs may be associated with COPD.

Paratracheal air cysts on thoracic multidetector CT: incidence, morphological characteristics and relevance to pulmonary emphysema.

OBJECTIVE: To determine the incidence, morphological characteristics and relevance of paratracheal air cysts (PTACs) with pulmonary emphysema, as seen on thoracic multidetector CT (MDCT). METHODS: The CT images of 854 consecutive patients who underwent thoracic MDCT during a period of 2 months at our institution were reviewed. 538 of the patients were male and 316 were female. The incidence, size and shape of the PTACs and their relation to pulmonary emphysema were retrospectively analysed. RESULTS: Among the 854 patients, 69 (8.1%) had PTACs. 37 (6.9%) of the 538 male patients and 32 (10.1%) of the 316 female patients had PTACs. The highest prevalence of PTACs (25 patients, 11.2%) was found in those who were in the sixth decade of life. 48 (69.6%) PTACs measured 3-10 mm at the longest diameter and 33 (47.8%) were elongated on the coronal section images. 12 (17.4%) patients with PTACs had underlying gross morphological emphysema. The relationship between the presence of PTACs and the presence of emphysema and the relationship between the presence of PTACs and the severity of emphysema were not statistically significant. The size of PTACs showed an inverse relation to the severity of emphysema. CONCLUSION: The incidence of PTACs was estimated to be much higher than that of previous studies. There was a slight female predilection for PTACs, most commonly found in the sixth decade of life; PTACs mostly measured 3-10 mm and were elongated in shape. The relation of PTACs to gross morphological emphysema was low. ADVANCES IN KNOWLEDGE: PTACs are not correlated with the presence of emphysema on MDCT.

[Benign cysts of the mediastinum: series of 28 cases]. / Les kystes bénins du médiastin : à propos de 28 cas.

INTRODUCTION: Benign cystic mediastinal mass form a group of heterogeneous and uncommon lesions. Surgical resection is the gold standard in these conditions. We reported our institutional experience in management of these benign tumours. In this review, cardiac and ganglionary benign mass were excluded. METHODS: We retrospectively reviewed the records of 28 patients with benign cysts of the mediastinum, who are operated in our department between January 2003 and December 2009 (7years period). RESULTS: There were 13 females (46.4%) and 15 males (53.5%), with a mean age of 36.8years (range: 13-63years). Most lesions (n=22) were equally in the anterior and middle mediastinum, only six were in the posterior mediastinum. Seventeen patients (60.7%) were symptomatic, with chest pain and cough as the most common symptoms. The diagnosis of mediastinal cyst was fortuitous in 11 patients with the waning of an assessment made for another reason. Surgery was indicated in all patients in order to both diagnostic and therapeutic. Posterolateral thoracotomy incision is the most common. Complete resection of the cyst was possible only in 18 cases (64.3%), whereas in ten (35. 7%) other cases part of the cyst was left in place due to tight adhesions to vital structures. After histological study, there were: nine bronchogenic cysts (32.1%), seven hydatid cysts (25%), four cystic lymphangiomas (14.3%), three mature cystic teratomas (10.7%) and three pleuropericardial cysts, one thymic cyst and one parathyroid cyst. The postoperative course was uneventful and no recurrence has been observed until now. CONCLUSION: The benign cysts of the mediastinum is a rare entity, the hydatid etiology remains common in our context. Surgical treatment remains the treatment of choice for mediastinal cysts, when the patient is operable, to save the risk of complications or degeneration.

Investigating links between polychlorinated biphenyl (PCB) exposure and thymic involution and thymic cysts in harbour porpoises (Phocoena phocoena).

The associations between polychlorinated biphenyls (PCBs) exposure and involution of lymphoid tissue and development of epithelial-lined cysts in the thymus of UK-stranded harbour porpoises (Phocoena phocoena) (n=170) were tested. Percentage of thymic lymphoid tissue (%TLT) was histologically quantified. Multiple regression analyses (n=169) demonstrated significant positive correlation between %TLT and nutritional status (p<0.001) and significant negative association between %TLT and onset of sexual maturity (p<0.001). However, in a subgroup of porpoises with total PCB levels above a proposed threshold of toxicity (>17mg/kg lipid weight) (n=109), the negative association between %TLT (as dependent variable) and summed blubber concentrations of 25 chlorobiphenyl congeners (∑25CBs) remained significant (p<0.01) along with nutritional status (p<0.001) and onset of sexual maturity (p<0.001). These results suggest PCB-induced immuno suppression may be occurring in harbour porpoises in UK waters but only at concentrations that exceed proposed toxicity thresholds for marine mammals. In contrast, development of thymic cysts appears predominantly age-related.

Prevalence and characteristics of paratracheal air cysts and their association with emphysema in a general population.

BACKGROUND: To evaluate the prevalence and characteristics of paratracheal air cysts and their association with emphysema and gender in a general population using low-dose computed tomography scanning of the chest. MATERIALS AND METHODS: We retrospectively enrolled a total of 924 patients (584 women, 340 men; mean age, 59.73 years; range, 37-89 years) who had received low-dose computed tomography scanning for health examination during the period January 1, 2010 to June 30, 2010. Computed tomographic images were evaluated for the presence of paratracheal air cysts. If paratracheal air cysts were identified, the lungs were reconstructed as a three-dimensional model on a commercial workstation. An emphysema index, an objective quantification of the extent of emphysematous changes on CT imaging, was defined as the percentage area of lung with attenuation values below -950 Hounsfield units. RESULTS: A total of 60 patients with paratracheal air cysts were included in this study (estimated prevalence, 6.5%; 12 men, 48 women; mean age, 59.85; range 45-89 years). Emphysema index differed significantly between genders (P<0.0001). The prevalence of paratracheal air cysts in men was significantly lower than that in women (P=0.005); however, the emphysema index in patients of both genders showed no evidence of emphysema. The majority (95%) of paratracheal air cysts were at the level of the seventh cervical to the second thoracic vertebrae. CONCLUSION: The presence of paratracheal air cysts is a common condition in general populations and should not be misdiagnosed as abnormal paratracheal free air. Paratracheal air cysts are more common in woman than in man. In our study, there is no patient with paratracheal air cysts has CT evidence of emphysema.

Paratracheal air cysts using low-dose screening chest computed tomography: clinical significance and imaging findings.

PURPOSE: The aim of this study was to evaluate the prevalence and clinical relevance of paratracheal air cysts in a general population who underwent low-dose computed tomography (LDCT). MATERIALS AND METHODS: From July 2005 to March 2008, a total of 2002 persons underwent LDCT and were included in the study. We retrospectively reviewed the chest CT images and analyzed the location, level, and size of the air cysts. We checked whether the cysts had communication with the trachea. Other abnormalities of the lung were noted. We evaluated whether the presence of paratracheal air cysts is associated with abnormal pulmonary function. RESULTS: In all, 75 persons (3.7%) had 77 paratracheal air cysts: 76 (98.7%) at the right side and 36 (46.7%) at the level of the T2 vertebral body. The mean anteroposterior diameter of the paratracheal air cysts was 7.5 mm, and mean transverse diameter was 4.2 mm. Altogether, 26 paratracheal air cysts (33.8%) showed communication with the trachea. Only two persons had respiratory symptoms. Pulmonary function tests showed that five patients (6.7%) had an obstructive pattern. CONCLUSION: The paratracheal air cysts were mostly located at the right side of the trachea and at the thoracic inlet level. One-third had communication with the trachea. Paratracheal air cysts are not associated with respiratory symptoms or obstructive lung disease clinically or radiologically.

[Benign primary cystic lesions of mediastinum in adult: the clinical spectrum and surgical treatment]. / Lesiones quísticas primarias y benignas del mediastino en el adulto: espectro clínico y tratamiento quirúrgico.

BACKGROUND AND OBJECTIVE: The mediastinal cysts form a group of heterogeneous and uncommon benign lesions of neoplastic, congenital, or inflammatory conditions. The forgoing controversy is how to manage them; surgical removal or observation. We reviewed our experience including some rare conditions, emphasizing the clinical spectrum and surgical treatment. PATIENTES AND METHODS: This is a retrospective review between 2000 and 2007 included 34 cases of primary mediastinal cystic lesions. Clinical features, imaging techniques, surgical operation, morbidity, mortality and follow-up were analyzed. RESULTS: There were 18 females (53%) and 16 males (47%), with a mean age+/-standard deviation of 45.3+/-14.1 years (range: 22-74). Most of cysts were congenital (94%), except patients with hydatid disease (6%). 24% of cysts (n=8) were detected in anterior mediastinum. Rest of them (n=26) were located in visceral mediastinum. Patients usually were symptomatic (61%). Chest pain and discomfort was most common symptom, others were dyspnea, cough and hemoptysis, respectively. Cysts excision was performed in all cases with an uneventful recovery and with no recurrence in long term follow up. CONCLUSIONS: Asymptomatic mediastinal cysts are not rare. Surgery is a reliable method of treatment of mediastinal cysts with acceptable mortality and morbidity.

[The cysts and fistulas of the neck in material of Otolaryngology Department of Rydygier District Hospital in Cracow]. / Torbiele i przetoki szyi w materiale oddzialu Otolaryngologii Wojewódzkiego Szpitala Specjalistycznego im L. Rydygiera w Krakowie w latach 1997-2007.

The retrospective study describes 118 patients treated for congenital cysts and fistulas of the neck between 1997 and 2007 in ORL Department of Rydygier District Hospital in Cracow. Malformation was divided into midline and laterocervical region anomalies. Malformation of midline included thyreoglossal duct and dermoid cyst. The most common malformation of laterocervical were cysts followed by fistulas. The theory of development, method of diagnosis and operative management were presented. Complication and recurrences were rare. Proper differential diagnosis and radical operation led to successful cure.

[Primary cysts and tumors of the mediastinum]. / Cistos e tumores primários do mediastino.

OBJECTIVE: To assess results in patients with primary cysts and tumours of the mediastinum who under- went surgery. METHODS: A retrospective single-centre study was undertaken into patients with primary cysts and tumours of the mediastinum who underwent surgery between January 1992 and December 2004. We analysed demographic data, clinical presentation, type of surgery carried out and procedure, lesion location and histological diagnosis. Predictive malignancy factors were also evaluated. Postoperative morbidity and mortality were noted, as was medium-term results. RESULTS: 171 patients underwent surgery over a 13-year period; 73 female (43%) and 98 male (57%). Mean age was 40.3+/-19.7 years (20 days-78 years). A primary cystic lesion was present in 15 patients (9%). The pri- mary tumours included thymic neoplasms (31%), lymphoma (22%), neurogenic tumours (16%), germ cell tumours (9%) and a miscellaneous group (13%). Malignant neoplasms were present in 78 patients (46%). The antero-superior mediastinum was the most commonly involved site to have a primary cyst or tumour (58%), followed by the posterior mediastinum (24%) and the middle mediastinum (18%). Symptoms were present in 68% of the patients and included chest pain (20%), fever and chills (13%), myasthenia gravis (11%), cough (10%), dyspnoea (10%), and superior vena caval syndrome (7%). Univariate analysis identified symptoms as a predictive factors of malignancy (p<0.001). Types of surgery carried out included postero-lateral thoracotomy (64 patients), median sternotomy (51 patients), anterior mediastinostomy (27 patients), antero-lateral thoracotomy (18 patients), video-assisted thoracic surgery (9 patients) and mediastinoscopy (2 patients). Total excision was performed in 116 patients, enlarged resection in 8 patients, subtotal re- section in 7 patients and biopsy in 40 patients. There was one postoperative death (0.6%). Follow-up was available in 165 patients (96.5%) and ranged from 34 days to 13.4 years (mean 5.7+/-4.0 years). Complementary treatment with chemo and/or radiotherapy was provided in 75 patients. Six patients had to be reoperated on for local recurrence (3) or metastasis (3) of the primary lesion. Fifteen patients died of their disease during the follow-up period. Actuarial survival at five years was 97.6% for benign lesions and 76.4% for malignant tumours. CONCLUSION: Results support surgical resection for benign lesions and an aggressive multimodal approach for malignant tumours.

Surgical management of mediastinal lesions.

Mediastinal tumors and cysts are relatively uncommon lesions requiring histologic confirmation. This retrospective study reports the experience of our department in the diagnosis and treatment of mediastinal lesions. Mediastinal lesions that were surgically treated in 200 patients aged 6-84 years, during a period of 28 years, were included in this series. Sixty patients had an apparently non-resectable lesion or lymphadenopathy of the anterior superior mediastinum. They had an anterior mediastinotomy and biopsy of the mediastinal lesion. No perioperative deaths were recorded in those patients. There were recorded 5 (8.3%) complications. Histological diagnosis was established in all patients: lymphoma (n = 21), metastatic carcinoma (n = 16), thymic lesions (n = 10), germ cell tumor (n = 3), other lesions (n = 10). The remainder 140 patients underwent a resection of the mediastinal lesion. One (0.7%) perioperative death and 21 (15%) complications were recorded. The histological diagnosis of the excised lesions was: thymic lesions (n = 60), neural tumors (n = 21), thyroid lesions (n = 14), bronchial cysts (n = 12), pericardial cysts (n = 10), germ cell tumors (n = 6), other lesions (n = 17). Our results are compared favorably with those reported in international literature. Surgery is the management of choice for patients with mediastinal lesions. It allows for establishing certain histological diagnosis and curative excision of the lesion, when it is necessary, with low operative risk.

Pericardial cyst: case reports and a literature review.

Pericardial cysts are rare mediastinal abnormalities, which are usually congenital but may also be acquired after cardiothoracic surgery. Cysts frequently occur in the right cardiophrenic angle and their diagnosis is usually suspected after an abnormal chest X ray is obtained. The presence of a pericardial cyst in this typical location or, less frequently, in an unusual location, poses a diagnostic challenge in distinguishing it from other intracardiac or mediastinal abnormalities. Two-dimensional echocardiography and transesophageal echocardiography are extremely valuable in diagnosing the presence of a pericardial cyst. Although most pericardial cysts are asymptomatic, patients may present with chest pain and dyspnea. In addition, life-threatening complications such as pericardial tamponade have been reported in association with pericardial cysts. The following cases illustrate the usefulness of two-dimensional echocardiography in making an accurate diagnosis of a pericardial cyst, as well as in follow-up of these patients for the development of possible complications.

[Multicenter experience of video-assisted thoracic surgery to treat mediastinal cysts and tumors]. / Experiencia multicéntrica de cirugía videotoracoscópica en el tratamiento de quistes y tumores del mediastino.

OBJECTIVE: In spite of improvements in imaging techniques, surgical procedures are often needed to diagnose and definitively treat mediastinal masses. The range of application of video-assisted thoracic surgery (VATS) in this context is still poorly defined. The present study describes and analyzes the experience of the Cooperative Group for Video-assisted Thoracoscopic Surgery of the Spanish Society of Pneumology and Thoracic Surgery (GCCVT-SEPAR), with the aim of determining the usefulness of the technique for treating mediastinal cysts and tumors. METHOD: For 2 years we gathered information prospectively on 1,573 consecutive VATS procedures in 17 hospitals. The data from 64 procedures performed for diagnosis and treatment of mediastinal cysts and tumors are analyzed. RESULTS: A definitive diagnosis was reached in all cases. Nineteen were malignant tumors and 45 were benign lesions. Twenty-five complete resections (39%) were performed: 6 pleuropericardial cysts, 4 bronchogenic cysts, 8 neurogenic tumors and other benign lesions. Radiologically poorly defined masses and those located in the anterior and median parts of the mediastinum were most often the object of diagnostic procedures, whereas cysts and well-defined solid lesions on the posterior mediastinum were usually the object of therapeutic interventions. Eleven percent of the cases required conversion to thoracotomy, mainly due to pleural adhesions. Four complications (6.3%) were recorded and no deaths occurred. The median hospital stay after surgery was 2.5 days; 7.8% of the procedures were performed on outpatients. CONCLUSIONS: VATS is performed on many mediastinal lesions in Spain. Cysts and benign tumors are selected for resection. Poorly defined and malignant lesions were diagnosed by biopsy. The experience reported demonstrates the efficacy and safety of this technique for selected cases.