Signal intensity characteristics of mediastinal cystic masses on T1-weighted MRI

Chest Magnetic Resonance Imaging: Advances and Clinical Care

Many promising study results as well as technical advances for chest magnetic resonance imaging (MRI) have demonstrated its academic and clinical potentials during the last few decades, although chest MRI has been used for relatively few clinical situations in routine clinical practice. However, the Fleischner Society as well as the Japanese Society of Magnetic Resonance in Medicine have published a few white papers to promote chest MRI in routine clinical practice. In this review, we present clinical evidence of the efficacy of chest MRI for 1) thoracic oncology and 2) pulmonary vascular diseases.

Canadian Society of Thoracic Radiology/Canadian Association of Radiologists Clinical Practice Guidance for Non-Vascular Thoracic MRI

Historically thoracic MRI has been limited by the lower proton density of lung parenchyma, cardiac and respiratory motion artifacts and long acquisition times. Recent technological advancements in MR hardware systems and improvement in MR pulse sequences have helped overcome these limitations and expand clinical opportunities for non-vascular thoracic MRI. Non-vascular thoracic MRI has been established as a problem-solving imaging modality for characterization of thymic, mediastinal, pleural chest wall and superior sulcus tumors and for detection of endometriosis. It is increasingly recognized as a powerful imaging tool for detection and characterization of lung nodules and for assessment of lung cancer staging. The lack of ionizing radiation makes thoracic MRI an invaluable imaging modality for young patients, pregnancy and for frequent serial follow-up imaging. Lack of familiarity and exposure to non-vascular thoracic MRI and lack of consistency in existing MRI protocols have called for clinical practice guidance. The purpose of this guide, which was developed by the Canadian Society of Thoracic Radiology and endorsed by the Canadian Association of Radiologists, is to familiarize radiologists, other interested clinicians and MR technologists with common and less common clinical indications for non-vascular thoracic MRI, discuss the fundamental imaging findings and focus on basic and more advanced MRI sequences tailored to specific clinical questions.

Imaging of the Middle and Visceral Mediastinum

The visceral mediastinum contains important vascular and non-vascular structures including the heart, great vessels, lymph nodes, and portions of the esophagus and trachea. Multiple imaging modalities, including chest radiography, computed tomography, MR imaging, and nuclear medicine studies, can be used to detect, diagnose, and characterize masses in this compartment. Lymphadenopathy is the most common process involving the visceral mediastinum and can be seen with a wide variety of diseases. Less commonly seen entities include foregut duplication cysts, neoplasms and other lesions arising from the trachea and esophagus, paragangliomas as well as other mesenchymal tumors.

Pictorial Review of Mediastinal Masses with an Emphasis on Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) has become a crucial tool for evaluating mediastinal masses considering that several lesions that appear indeterminate on computed tomography and radiography can be differentiated on MRI. Using a three-compartment model to localize the mass and employing a basic knowledge of MRI, radiologists can easily diagnose mediastinal masses. Here, we review the use of MRI in evaluating mediastinal masses and present the images of various mediastinal masses categorized using the International Thymic Malignancy Interest Group's three-compartment classification system. These masses include thymic hyperplasia, thymic cyst, pericardial cyst, thymoma, mediastinal hemangioma, lymphoma, mature teratoma, bronchogenic cyst, esophageal duplication cyst, mediastinal thyroid carcinoma originating from ectopic thyroid tissue, mediastinal liposarcoma, mediastinal pancreatic pseudocyst, neurogenic tumor, meningocele, and plasmacytoma.

Application of endoscopic ultrasound-guided-fine needle aspiration combined with cyst fluid analysis for the diagnosis of mediastinal cystic lesions

BACKGROUND

Mediastinal cystic lesions account for approximately 15-20% of all mediastinal masses and are difficult to differentiate because of similar imaging manifestation. The aim of this study was to differentiate mediastinum cystic lesions through endoscopic ultrasound-guided-fine needle aspiration (EUS-FNA) and parameters from cyst-fluid analysis.

METHODS

Over a period of eight years, 37 patients suspected with mediastinal cystic lesions were assessed. Cyst fluid was collected via EUS-FNA and further examined using cytological and biochemical techniques. Definitive diagnosis was established based on cytology, surgical pathology, and/or clinical follow-up.

RESULTS

Based on the final pathological reports or long-term follow-up, 19 patients were diagnosed with benign cysts, 14 with benign or malignant tumors, 2 with tuberculosis, 1 with an abscess, and 1 with a pancreatic pseudocyst. Computed tomography or magnetic resonance imaging mistakenly distinguished eight cases as solid masses (27.03%), but EUS revealed cystic characteristics. Carcinoembryonic antigen and lactate dehydrogenase (LDH) were evaluated from the cyst fluid obtained by EUS-FNA. There was no statistically significant difference in carcinoembryonic antigen values between benign and malignant cysts; however the average LDH value in the malignancy group was significantly higher than in the benign group.

CONCLUSION

EUS-FNA showed great potential for differentiating mediastinal lesions by combining imaging manifestation and cytological examination. The elevated LDH value from cyst fluid chemical analysis could be used as an auxiliary indicator for diagnosing malignancy.

Mediastinal and Pleural MR Imaging: Practical Approach for Daily Practice

Radiologists in any practice setting should be prepared to use thoracic magnetic resonance (MR) imaging for noncardiac and nonangiographic applications. This begins with understanding the sequence building blocks that can be used to design effective thoracic MR imaging protocols. In most instances, the sequences used in thoracic MR imaging are adapted from protocols used elsewhere in the body. Some modifications, including the addition of electrocardiographic gating or respiratory triggering, may be necessary for certain applications. Once protocols are in place, recognition of clinical scenarios in which thoracic MR imaging can provide value beyond other imaging modalities is essential. MR imaging is particularly beneficial in evaluating for benign features in indeterminate lesions. In lesions that are suspected to be composed of fluid, including mediastinal cysts and lesions composed of dilated lymphatics, MR imaging can confirm the presence of fluid and absence of suspicious enhancement. It can also be used to evaluate for intravoxel lipid, a finding seen in benign residual thymic tissue and thymic hyperplasia. Because of its excellent contrast resolution and potential for subtraction images, MR imaging can interrogate local treatment sites for the development of recurrent tumor on a background of post-treatment changes. In addition to characterization of lesions, thoracic MR imaging can be useful in surgical and treatment planning. By identifying nodular sites of enhancement or areas of diffusion restriction within cystic or necrotic lesions, MR imaging can be used to direct sites for biopsy. MR imaging can help evaluate for local tumor invasion with the application of "real-time" cine sequences to determine whether a lesion is adherent to an adjacent structure or surface. Finally, MR imaging is the modality of choice for imaging potential tumor thrombus. By understanding the role of MR imaging in these clinical scenarios, radiologists can increase the use of thoracic MR imaging for the benefit of improved decision making in the care of patients. ^©RSNA, 2018.

Incremental Value of Magnetic Resonance Imaging in Further Characterizing Hypodense Mediastinal and Paracardiac Lesions Identified on Computed Tomography

Mediastinal and paracardiac lesions are usually first diagnosed on a chest radiograph or echocardiogram. Often, a computed tomography is obtained to further delineate these lesions. CT may be suboptimal for evaluation of enhancement characteristics and direct extension into the adjacent mediastinal structures. With its intrinsic superior soft-tissue characterization, magnetic resonance imaging (MRI) can better delineate these lesions, their internal tissue characteristics, and identify adhesion/invasion into adjacent structures. This pictorial essay provides a brief synopsis of the key MRI sequences and their utility in further characterizing mediastinal and paracardiac lesions.

Pulmonologist's Road Map to Mediastinal Lymph Node Imaging

Mediastinal lymph node station maps are intended to facilitate nodal staging in patients with non-small cell lung cancer. These maps have been revised over time and the International Association for Study of Lung Cancer (IASLC) map is the latest rendition. This article illustrates the imaging appearance of each of the IASLC map mediastinal lymph node stations, overviews some of the mediastinal lymph node sampling techniques, and discusses common pitfalls of the IASLC map. It also reviews mediastinal anatomic variants and pathologic features that may simulate lymphadenopathy.

MR Imaging of Mediastinal Masses

The high soft tissue contrast of MR imaging enables superior tissue characterization of mediastinal masses, adding diagnostic specificity and often changing and benefiting clinical management. MR imaging can better discern cystic from solid content and can detect microscopic fat, hemorrhage, and fibrous content within lesions. In many cases, mediastinal MR imaging may prevent unnecessary diagnostic intervention. In other cases, MR imaging may indicate the optimal site for biopsy or the correct compartment for resection. Awareness of the efficacy of MR imaging with regard to mediastinal mass characterization and judicious MR imaging utilization should further improve patient care.

Foregut duplication of the stomach diagnosed by endoscopic ultrasound guided fine-needle aspiration cytology: case report and literature review

Gastric duplication cyst (GDC) with a pseudostratified columnar ciliated epithelium is an uncommon malformation supposed to originate from a respiratory diverticulum arising from the ventral foregut. Morphologic appearance of GDCs is variable, depending on the density of their contents. GDCs are often misdiagnosed as solid masses by imaging techniques, and as a consequence they may be wrongly overtreated. We report our case of a 56-year-old man with a 5 cm hypoechoic mass of the gastroesophageal junction, incidentally detected by transabdominal ultrasonography. Neither transabdominal ultrasonography nor magnetic resonance clearly outlined the features of the lesion. The patient underwent endoscopic ultrasound (EUS), which showed a hypoechoic mass arising from the fourth layer of the anterior gastric wall, just below the gastroesophageal junction. According to EUS features, a diagnosis of gastrointestinal stromal tumor was suggested. EUS-guided fine-needle aspiration cytology revealed a diagnosis of GDC with pseudostratified columnar ciliated epithelium. We therefore performed an endoscopically-assisted laparoscopic excision of the cyst.

In conclusion, whenever a subepithelial gastric mass is found in the upper part of the gastric wall, a duplication cyst, although rare, should be considered. In this case, EUS-guided fine-needle aspiration cytology could provide a cytological diagnosis useful to arrange in advance the more adequate surgical treatment.

[Benign primary cystic lesions of mediastinum in adult: the clinical spectrum and surgical treatment]

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 utility and the safety of EUS-guided FNA in the evaluation of duplication cysts

BACKGROUND

Diagnosis of a foregut duplication cyst is of great clinical impact. A definitive diagnosis of a foregut duplication cyst can avert the need for major thoracic surgery in the otherwise asymptomatic individual. This study sought to evaluate the safety and the utility of EUS and EUS-guided FNA (EUS-FNA) in the diagnosis of foregut duplication cysts.

METHODS

Over a period of 4 years, 4771 patients underwent EUS for various indications at two EUS referral centers. EUS findings were consistent with a mediastinal cyst in 30 cases. EUS-FNA was performed in 22 patients. A definitive diagnosis was established based on cytology, surgical pathology, and/or clinical follow-up. FNA was done with 22-gauge needles and antibiotic prophylaxis.

RESULTS

The appearance of cyst contents on EUS ranged from completely anechoic (23 cases) to hypoechoic (7 cases). Hypoechoic cystic lesions contained echogenic foci. All anechoic lesions were confirmed as benign duplication cysts based on cytology, pathology, and clinical follow-up. Hypoechoic cystic lesions were confirmed to be benign duplication cysts in 4 cases. Three cases proved to be malignant or granulomatous necrotizing lymph nodes. No periprocedural complications occurred.

CONCLUSIONS

Variation exists in the EUS appearance of benign mediastinal cysts. EUS-FNA of mediastinal cysts with smaller-gauge needles, and antibiotic prophylaxis appears safe and can provide a definitive diagnosis in atypical mediastinal cystic lesions.

Imaging Evaluation of Pediatric Mediastinal Masses

Mediastinal masses in children are a heterogeneous group of asymptomatic to potentially life-threatening congenital, infectious, or neoplastic lesions that can present complex diagnostic and therapeutic dilemmas. This article presents the imaging features of the common mediastinal masses seen in the pediatric population. Classification of the masses is performed according to the traditional mediastinal compartment model, consisting of the anterior, middle, and posterior mediastinum. This scheme facilitates differentiation of the variety of disorders.

CT and MR imaging findings of benign cardiac tumors

This imaging review describes the appearance of benign cardiac tumors on CT and MRI. Although rare, benign tumors outnumber their primary malignant counterparts three to one. Since mortality varies directly with invasion, identifying the neoplasm at an early stage helps focus treatment, especially in benign cases, which generally respond well to surgical resection. In adults and children, myxomas and rhabdomyomas, respectively, represent the most common benign tumors, which can be grouped into tissue-specific subtypes, such as rhabdomyomas, fibromas, lipomas, teratomas, etc. Besides their variable prevalence in particular age groups, these tumors also differ with regard to their gender predilection, location, and number. For example, myxomas appear predominantly in women and generally as a solitary mass in the left or right atrium, whereas rhabdomyomas present equally in boys and girls and chiefly as multiple masses in the ventricles. Despite their differences, however, both types share an association with heritable syndromes like the Carney complex for myxomas and tuberous sclerosis for rhabdomyomas. As with all cardiac tumors, echocardiographic findings usually suggest the initial diagnosis but cross-sectional imaging with CT and MRI can help resolve diagnostically challenging cases. For example, with its direct multiplanar capability, excellent contrast resolution, and large field of view, MRI permits a detailed examination of the entire mediastinum, helping to rule out an equivocal mass on echocardiography. Through dynamic techniques, MRI, in addition to morphologic characterization, can depict the pathophysiological effects of these tumors, for instance, with regard to myocardial contraction, valvular function, or blood flow.

[Role of ultrasound-guided endoscopy in the evaluation of mediastinal lesions]

The evaluation of the mediastinum is still a challenge. In most cases, a pathologic study is mandatory for therapeutic decision-making. In this setting, endoscopic ultrasonography (EUS) without and with fine needle aspiration (FNA) is currently considered as a very useful and safe non-invasive technique since it overcomes most problems raising from standard radiologic techniques at the time of obtaining histologic confirmation. Moreover, it avoids the surgical approach for diagnosis in a significant number of patients. Thus, performance characteristics (sensitivity, specificity and accuracy) of EUS FNA in the diagnosis of mediastinal lymph nodes of unknown origin are higher than 90%. The place of EUS FNA in the staging of lung cancer is not well established yet, but available data suggest that it can play a major role in patients with negative transbronchial biopsy or even in the initial evaluation regardless of CT results. Finally, recent studies also suggest that EUS FNA is the most cost-effective non-surgical technique for the study of the mediastinum.

Laparoscopic resection of intra-abdominal esophageal duplication cyst

Esophageal duplication cysts are frequently encountered in the mediastinum and rarely in the abdomen. A case of laparoscopic resection of an intra-abdominal esophageal duplication cyst is reported. An incidental 4.5 x 4.0 x 3.5-cm, well-circumscribed, homogenous mass anterior to the intra-abdominal esophagus was detected on staging CT examinations for breast cancer in a 51-year-old woman. Laparoscopic resection of the lesion was performed after completion of breast-conserving surgery and whole breast irradiation. The defect of the muscular layer of the esophagus caused by the complete removal of the lesion required repair with muscular sutures. It was helpful to inspect the integrity of the esophageal wall repair by examining the exterior wall of the esophagus laparoscopically while insufflating air into the esophageal lumen through a fiberoptic esophagoscope. A laparoscopic approach utilizing intraoperative esophagoscopy is easy and safe for removal of intra-abdominal esophageal duplication cysts.

Imaging of cystic masses of the mediastinum

Cystic masses of the mediastinum are well-marginated round lesions that contain fluid and are lined with epithelium. Major cystic masses include congenital benign cysts (ie, bronchogenic, esophageal duplication, neurenteric, pericardial, and thymic cysts), meningocele, mature cystic teratoma, and lymphangioma. Many tumors (eg, thymomas, Hodgkin disease, germ cell tumors, mediastinal carcinomas, metastases to lymph nodes, nerve root tumors) can undergo cystic degeneration-especially after radiation therapy or chemotherapy-and demonstrate mixed solid and cystic elements at computed tomography (CT) or magnetic resonance (MR) imaging. If degeneration is extensive, such tumors may be virtually indistinguishable from congenital cysts. A mediastinal abscess or pancreatic pseudocyst also appears as a fluid-containing mediastinal cystic mass. However, clinical history and manifestations, anatomic position, and certain details seen at CT or MR imaging allow correct diagnosis in many cases. Familiarity with the radiologic features of mediastinal cystic masses facilitates accurate diagnosis, differentiation from other cystlike lesions, and, thus, optimal patient treatment.

Thoracoscopic resection of unusual symptomatic pericardial cysts

Pericardial cysts are mediastinal tumors that usually have a benign course. Diagnostic and therapeutic thoracoscopy are warranted for suspect mediastinal masses, unsuccessful nondiagnostic less invasive procedures, and symptomatic unusually located pericardial cysts. We report a case of thoracoscopic resection of symptomatic pericardial cysts.

Evaluation of mediastinal masses by endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration

OBJECTIVE

Interest has been growing in using endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration in the evaluation of mediastinal masses. The purpose of this study was to review the spectrum of mediastinal masses encountered using endoscopic ultrasound.

METHODS

We reviewed all cases of mediastinal masses examined by endoscopic ultrasound, with or without endoscopic ultrasound-guided fine needle aspiration, prospectively gathered from our electronic database from April 1995 to July 2000.

RESULTS

Of 1447 upper endoscopic ultrasound examinations, 33 (2.3%) involved a mediastinal mass. Sixty-one percent of the patients were male and the average age was 65 yr. Fifty-five percent of patients had dysphagia, 48 percent experienced weight loss, and only 12 percent were totally asymptomatic. Seventy-three percent had masses by chest CT. Sixty-seven percent were ultimately found to be malignant, 21 percent were solid benign lesions, and four were cystic. Only two lesions were resected. Endoscopic ultrasound-guided fine needle aspiration was used in 76 percent of all patients. The median survival of patients with malignant lesions was only 87 days.

CONCLUSIONS

Lesions of the deep mediastinum are often difficult to conclusively diagnose with nonendoscopic studies. Endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration can easily access this region to aid in the diagnosis and management of these lesions.

Pedunculated bronchogenic cyst mimicking pleural lesion

We report a rare case of a bronchogenic cyst presenting as a pleural nodule. CT and MRI demonstrated a well circumscribed, homogeneous lesion located on the pleural surface apart from the mediastinum. It was proven to be a bronchogenic cyst localized between the parietal and visceral pleurae and connected with the mediastinum only through fibrous tissue. Radiologists should be aware that a mediastinal bronchogenic cyst may be located apart from the mediastinum.

Clinical features and management of bronchogenic cysts: report of 17 cases

Between 1966 and 1996, 17 patients, comprising 1 child and 16 adults, underwent surgical treatment for bronchogenic cysts at the National Cancer Center Hospital. The bronchogenic cysts were located in the mediastinum in 11 patients and in the pulmonary parenchyma in 6. Of the 17 patients, 5 (29.4%) manifested symptoms, being more frequently seen in those with intrapulmonary cysts than in those with mediastinal cysts. Chest radiographs were ineffective for accurate preoperative diagnosis, but accurate diagnosis was possible with 69.2% of computed tomography (CT) scans and 100% of magnetic resonance imaging (MRI) scans. MRI also proved very useful for qualitatively diagnosing the mediastinal tumors as cystic or solid. Surgery was performed through a thoracotomy in 14 patients and by video-assisted thoracic surgery (VATS) in 3 patients, achieving complete resection in 16 patients. In one patient, a mediastinal bronchogenic cyst was excised by VATS and incompletely resected because of tight adhesion to the membranous part of the trachea; however, no late complication or recurrence developed after the residual cystic wall had been ablated by electrocautery. VATS, which is an easy procedure to perform with only minimal surgical invasion, may be indicated for bronchogenic cysts if patients who undergo incomplete resection can be followed up carefully. Recent advances in imaging techniques have made it unnecessary to perform surgical excision for diagnostic confirmation, but we recommend surgery for most patients to relieve symptoms and prevent complications.

Cervicothoracic lesions in infants and children

Cervicothoracic lesions are not uncommon in children. All cervicothoracic lesions except superficial lesions extend from the neck to the thorax through the thoracic inlet. Evaluation of this area involves multiple imaging modalities: plain radiography, ultrasonography, nuclear medicine, computed tomography, and magnetic resonance (MR) imaging. However, MR imaging is the method of choice for assessing the full extents of cervicothoracic lesions and their relationships to neurovascular structures. Cervicothoracic lesions can be classified as congenital lesions, inflammatory lesions, benign tumors, malignant tumors, and traumatic lesions. Lymphangioma is the most common cervicothoracic mass in children; other congenital lesions include hemangioma, thymic cyst, and vascular anomalies. Inflammatory adenopathy reactive to tuberculosis, mononucleosis, tularemia, cat-scratch fever, infection with human immunodeficiency virus, or other upper respiratory tract infections can manifest as cervicothoracic lesions; tuberculous abscesses and abscesses of other origins can also be seen. Lipoma, lipoblastoma, aggressive fibromatosis, and nerve sheath tumors (either isolated lesions or those associated with neurofibromatosis) can also occur as cervicothoracic masses. Malignant cervicothoracic tumors include lymphoma, thyroid carcinoma, neuroblastoma, and chest wall tumors (rhabdomyosarcoma, Ewing sarcoma, and neuroectodermal tumor). Traumatic cervicothoracic lesions include pneumomediastinum of traumatic origin, traumatic pharyngeal pseudodiverticulum, esophageal foreign-body granuloma, and cervicothoracic hematoma.

Congenital thymic cysts in children--mostly misdiagnosed

BACKGROUND/PURPOSE

Thymic cysts are rare lesions of the neck and mediastinum that are difficult to diagnose. Often considered inconsequential, these lesions can frequently be symptomatic. In this report the authors contrast their experience with that of the literature.

METHODS

From 1984 through 1997, the authors encountered 14 patients with this lesion. All cysts were completely excised. Patients that had an acquired cyst of the thymus were excluded from this series.

RESULTS

Of the 14 patients ranging in age from 2 weeks to 16 years, seven patients had cervical masses, five had mediastinal masses, and two children had both sites involved. Seven children were symptomatic with wheezing and upper respiratory infection, with cough and fever being the most common clinical features. Investigations included chest radiograph, contrast esophagram, sonography (US) and computerized tomography (CT). Displacement of vital mediastinal or neck structures was observed in eight patients. Only two patients received correct diagnosis before surgery. Successful and complete excision of all cysts was achieved. The cysts were benign and ranged in size from 2 to 22 cm in diameter.

CONCLUSION

Often forgotten, thymic cysts are rare benign lesions that should be considered in the differential diagnosis of cervical and mediastinal masses in children.

Primary mediastinal tumors: part II. Tumors of the middle and posterior mediastinum

Lymphoma, mediastinal cysts, and neurogenic neoplasms are the most common primary middle and posterior mediastinal tumors. Lymphoma may involve the anterior, middle and/or posterior mediastinum, frequently as lymphadenopathy or as a discrete mass. Foregut cysts are common congenital mediastinal cysts and frequently arise in the middle mediastinum. Pericardial cysts are rare. Schwannoma and neurofibroma are benign peripheral nerve neoplasms, represent the most common mediastinal neurogenic tumors, and rarely degenerate into malignant tumors of nerve sheath origin. Sympathetic ganglia tumors include benign ganglioneuroma and malignant ganglioneuroblastoma and neuroblastoma. Lateral thoracic meningocele is a rare cause of a posterior mediastinal mass.

Mid-trimester prenatal sonographic diagnosis of a pericardial cyst

Prenatal diagnosis of pericardial masses are infrequent and usually consist of intrapericardial teratomas or haemangiomas. We present the first report of prenatal diagnosis of a suspected pericardial cyst at 14 weeks' gestation which was subsequently confirmed by neonatal computed tomography.