the differential diagnosis of mediastinal masses includes primary lung cancer , metastatic cancer , neurogenic tumor , cysts and infections.12 the bronchogenic cysts are the most common cystic lesions of the mediastinum.3 in some cases , these lesions could mimic solid masses.4 most patients with posterior mediastinal cysts are asymptomatic , and the cysts are discovered incidentally during other imaging studies .
the possible symptoms include chest pain , cough , dyspnea and dysphagia.356 the differentiation between a solid and cystic lesion by the imaging modalities available , such as computed tomography ( ct ) , magnetic resonance imaging ( mri ) and endoscopic ultrasonography ( eus ) , is not always easy.47 eus has provided a minimally invasive approach to the diagnosis of benign mediastinal cysts.8 in the largest retrospective study done to date , it has been demonstrated that a hypoechoic eus pattern does not exclude the diagnosis of a cyst.8 our report describes two cases of intramural bronchogenic cysts and reviews the role of eus in dealing with such cases .
an 80-year - old female was admitted to our hospital due to retrosternal pain , fever , coughing and weight loss of 20 pounds in a month .
a eus - guided fine needle aspiration ( fna ) of this lesion was indicated .
2 ) showed a paraesophageal anechoic round mass with a starry - sky pattern , negative doppler and posterior acoustic enhancement .
the follow - up showed good evolution and diminution of the cyst size 1 month later in the radiological control . a computed tomography - scan showing a mediastinal paraesophageal mass .
endoscopic ultrasonography with a linear array ultrasound endoscope showed an anechoic round mass with a starry - sky pattern and the needle inside the lesion .
a 42-year - old male was referred to our institution due to a submucosal lesion in the distal third of the esophageal wall .
it had a homogenous , hypoechoic aspect , with well defined borders , posterior acoustic enhancement , and measured 5 cm in its largest diameter .
the patient was discharged on the same day without treatment of antibiotics , and no infectious complications were observed during follow - up .
the lesion was homogenous , hypoechoic , with well defined borders and posterior acoustic enhancement .
an 80-year - old female was admitted to our hospital due to retrosternal pain , fever , coughing and weight loss of 20 pounds in a month .
a eus - guided fine needle aspiration ( fna ) of this lesion was indicated .
2 ) showed a paraesophageal anechoic round mass with a starry - sky pattern , negative doppler and posterior acoustic enhancement .
the follow - up showed good evolution and diminution of the cyst size 1 month later in the radiological control . a computed tomography - scan showing a mediastinal paraesophageal mass .
endoscopic ultrasonography with a linear array ultrasound endoscope showed an anechoic round mass with a starry - sky pattern and the needle inside the lesion .
a 42-year - old male was referred to our institution due to a submucosal lesion in the distal third of the esophageal wall .
it had a homogenous , hypoechoic aspect , with well defined borders , posterior acoustic enhancement , and measured 5 cm in its largest diameter .
the patient was discharged on the same day without treatment of antibiotics , and no infectious complications were observed during follow - up .
the lesion was homogenous , hypoechoic , with well defined borders and posterior acoustic enhancement .
an 80-year - old female was admitted to our hospital due to retrosternal pain , fever , coughing and weight loss of 20 pounds in a month .
a eus - guided fine needle aspiration ( fna ) of this lesion was indicated .
2 ) showed a paraesophageal anechoic round mass with a starry - sky pattern , negative doppler and posterior acoustic enhancement .
the follow - up showed good evolution and diminution of the cyst size 1 month later in the radiological control . a computed tomography - scan showing a mediastinal paraesophageal mass .
endoscopic ultrasonography with a linear array ultrasound endoscope showed an anechoic round mass with a starry - sky pattern and the needle inside the lesion .
a 42-year - old male was referred to our institution due to a submucosal lesion in the distal third of the esophageal wall .
it had a homogenous , hypoechoic aspect , with well defined borders , posterior acoustic enhancement , and measured 5 cm in its largest diameter .
the patient was discharged on the same day without treatment of antibiotics , and no infectious complications were observed during follow - up .
the lesion was homogenous , hypoechoic , with well defined borders and posterior acoustic enhancement .
about 46% to 67% of all mediastinal lesions are malignant.910 reported accuracy of diagnosis for malignant lesions in the mediastinum is only about 83%.11 therefore , it is important to perform a good evaluation of these lesions to avoid unnecessary surgical procedures .
bronchogenic cysts originate from the aberrant development of the ventral primitive foregut during embryonic development .
they share a similar developmental background with esophageal duplication cysts.34612 about 85% percent of bronchogenic cysts arise in the mediastinum in close relationship to the trachea , main bronchi , and carina .
occasionally , bronchogenic cysts become  engulfed  in the growing esophagus.13 eus can accurately distinguish a solid from a cystic lesion , and with fna it 's possible to collect materials from suspicious or atypical lesions.8 in comparison with the other imaging modalities ( ct and mri ) , eus is better at differentiating solid from cyst lesions.214 ct and mri may misdiagnosed a cystic duplication lesion as a solid lesion in about 70% of cases.2 the feature that distinguishes a cyst in eus is a round or tubular anechoic structure with a negative doppler signal and posterior acoustic enhancement.1 sometimes in eus examinations , bronchogenic cysts may resemble smooth muscle tumors and gastrointestinal stromal tumors ( gist ) due to their round or oval shape with well - defined borders and homogeneous and hypoechoic internal echo pattern .
the echogenicity can be attributed to the mucoid content of the cyst.8 in the first case , weight loss , fever and an apparent mediastinal solid lesion on ct raised the possibility of a lymphoma . the starry - sky pattern on eus probably correlated with the mucoid content of the cyst .
the lesion was hypoechoic and apparently with its origin at the fourth layer , raising the possibility of a gist .
mediastinal cyst biopsy is not always necessary and the literatures report cases of severe infection after eus - fna.81516 the use of antibiotics before and after the procedure has already been evaluated in small clinical studies with promising results.214 however , another study shows infectious complication after eus - fna despite the use of a prophylactic antibiotic.17 at the moment , there is no consensus regarding antibiotic prophylaxis use before eus - fna . in our cases ,
just the first patient received antibiotics and none of them had infectious complications after eus - fna .
there is little description in the literature about the macroscopic appearance of the material obtained from eus - fna .
the macroscopic appearance of the material collected from bronchogenic cysts with eus - fna was often described to be like mucoid / mucinous,3811 grayish white mucus,2 thick , brownish fluid,16 or yellowish fluid.14 in our cases , both patients had a mucous content in the material obtained by eus - fna .
bronchogenic cysts could be managed conservatively and/or by surgery depending on the clinical aspects of patients with this problem.18 finally , there is also controversy in the literature regarding the need to perform eus drainage of the cyst content . based on the infection risk related to eus - fna , some studies favored drainage,14 but not all of them.28 in our two cases , we did not perform eus drainage and the patients did not develop infectious complications related to eus - fna . in conclusion ,
they are rarely mediastinal lesions , which can explain the lack of more satisfying clinical trials and of more useful guidelines to assist physicians .
current literatures are still controversial about some points such as the need of eus - fna , eus - drainage and the use of antibiotic prophylaxis during interventional eus ( fna or drainage ) .
 the differentiation between a solid and cystic lesion is not always easy . 
 eus has provided a minimally invasive approach to the diagnosis of benign mediastinal cysts . 
 our report describes two cases of intramural bronchogenic cysts and reviews the role of eus in dealing with such cases . 
 we conclude that the bronchogenic cysts are still a challenge despite evolution of the imaging studies . 
INTRODUCTION
CASE REPORTS
None
Case 1
Case 2
DISCUSSION