T1 and T2 Mapping for Characterization of Mediastinal Masses: A Feasibility study.

Purpose: To evaluate the feasibility and usefulness of T1 and T2 mapping in characterization of mediastinal masses. Methods: From August 2019 through December 2021, 47 patients underwent 3.0-T chest MRI with T1 and post-contrast T1 mapping using modified look-locker inversion recovery sequences and T2 mapping using a T2-prepared single-shot shot steady-state free precession technique. Mean native T1, native T2, and post-contrast T1 values were measured by drawing the region of interest in the mediastinal masses, and enhancement index (EI) was calculated using these values. Results: All mapping images were acquired successfully, without significant artifact. There were 25 thymic epithelial tumors (TETs), 3 schwannomas, 6 lymphomas, and 9 thymic cysts, and 4 other cystic tumors. TET, schwannoma, and lymphoma were grouped together as "solid tumor," to be compared with thymic cysts and other tumors ("cystic tumors"). The mean post-contrast T1 mapping (P < .001), native T2 mapping (P < .001), and EI (P < .001) values showed significant difference between these two groups. Among TETs, high risk TETs (thymoma types B2, B3, and thymic carcinoma) showed significantly higher native T2 mapping values (P = .002) than low risk TETs (thymoma types A, B1, and AB). For all measured variables, interrater reliability was good to excellent (intraclass coefficient [ICC]: .869∼.990) and intrarater reliability was excellent (ICC: .911∼.995). Conclusion: The use of T1 and T2 mapping in MRI of mediastinal masses is feasible and may provide additional information in the evaluation of mediastinal masses.

Transesophageal endoscopic resection of mediastinal cysts (with video).

BACKGROUND AND AIMS: Primary mediastinal cysts are infrequent lesions derived from a variety of mediastinal organs or structures. Complete surgical resection is the treatment of choice even in asymptomatic patients to prevent severe adverse events (AEs) and to establish the diagnosis. Transesophageal endoscopic resection of benign mediastinal tumors has been proven feasible. The aim of this study was to evaluate the feasibility, safety, and efficacy of transesophageal endoscopic surgery for mediastinal cysts. METHODS: From January 2016 to May 2021, patients with mediastinal cysts who underwent transesophageal endoscopic resection were retrospectively included. Clinicopathologic characteristics, procedure-related parameters, AEs, and follow-up outcomes were analyzed. RESULTS: Ten patients with mediastinal cysts were included in this study. The mean cyst size was 3.3 ± 1.3 cm. Histopathology revealed 3 bronchogenic cysts (30.0%), 4 esophageal duplication cysts (40.0%), 2 gastroenteric cysts (20.0%), and 1 lymphatic cyst (10.0%). All procedures were performed uneventfully without conversion to traditional surgery. En-bloc resection was achieved in 6 patients (60.0%). Aggressive resection was avoided to prevent damage to the surrounding vital organs. Mean resection time and suture time were 58.0 ± 36.4 minutes and 5.4 ± 1.0 minutes, respectively. No major pneumothorax, bleeding, mucosal injury, or fistula occurred. One patient had a transient febrile episode (>38.5°C). Mean postoperative hospital stay was 2.7 ± .9 days. No residual or recurrent lesions were observed in any patient during a mean follow-up period of 29.8 ± 19.5 months. CONCLUSIONS: Transesophageal endoscopic surgery appears to be a feasible, safe, effective, and much less invasive approach for mediastinal cyst resection. Larger prospective studies are required to fully assess the efficacy and safety of this novel technique.

Special Computed Tomography Imaging Features of Thymic Cyst.

Objective: To explore the features and diagnostic value of computed tomography (CT) imaging in cases of thymic cysts. Methods: A total of 24 cases of the thymic cysts (confirmed by postoperative pathology) were retrospectively analyzed. The location, morphology, and density of the thymic cysts were summarized, and the changes in CT value of the region of interest (ROI) in the thymic cysts between noncontrast enhanced and enhanced chest scans were compared and classified. Results: The average long-axis dimension was 17.50 ± 6.00 mm, the CT value range across the 24 cases was 5-81 HU, and the average CT value of the noncontrast enhanced scans was 39.75 ± 20.66 HU. The CT value in the noncontrast enhanced scan was >20 HU in 79% of the sample cases. The CT value in the ROI of the thymic cysts under enhanced scan showed a significant decrease in 15 cases, a significant increase in 5 cases, and an insignificant change in 4 cases. Conclusion: The CT values of the thymic cysts in the enhanced scans were generally lower than in the noncontrast enhanced scans, which might be a valuable finding for thymic cysts diagnosis.

Exophytic cavernous hemangioma arising from the right ventricle: Report of a rare case.

Cardiac hemangioma is relatively rare, accounting for approximately 1-3% of all primary heart tumors. This benign tumor may be an incidental lesion, but can also cause arrhythmias, pericardial effusion, congestive heart failure or outflow obstruction. We report a rare case with exophytic cardiac hemangioma arising from the right ventricle. Echocardiography showed an approximately 40 mm round protruding mass on the anterior wall of the right ventricle. Cardiovascular magnetic resonance demonstrated isointense and hyperintense signals on T1- and T2-weighted images, respectively. These imaging studies suggested a pericardial cyst. Perioperative findings indicated a globular, exophytic mass, vascular in nature, arising from the right ventricle. The lesion was resected directly, and the space left by defect in the right ventricular wall was covered with a bovine pericardial patch. Cardiac hemangiomas are generally endoluminal tumors, but we must keep in mind that the differential diagnoses include various pericardial lesions by medical images.

Uncommon Location of a Giant Pericardial Cyst: A Case Report.

Pericardial cysts (PCs) are uncommon benign congenital anomalies residing in the middle mediastinum. The location of PCs is diverse with 70% of cases in the right cardiophrenic angle, 22% in the left cardiophrenic angle, and 8% in the posterior (as in our case) or superior anterior part of the mediastinum. In 2019, a 54-year-old woman was referred to the emergency department of Imam Khomeini Hospital Complex (Tehran, Iran) suffering from progressive shortness of breath. The chest computed tomography scan showed an unusual giant cystic lesion occupying >50% of the right hemithorax. The cystic lesion was primarily located in the posterior mediastinum. The patient underwent video-assisted thoracoscopic surgery (VATS), and the cyst was completely resected from the mediastinum. During past decades, several cases of PCs have been reported in different age and sex groups. Here, we present a case of a giant pericardial cyst (PC) located in the posterior mediastinum. The cyst was successfully resected using VATS. Only one other study has reported a PC in the posterior mediastinum.

Non-Neoplastic Mediastinal Cysts.

Primary mediastinal cysts are infrequent lesions that can arise from a variety of mediastinal organs or structures. Most of these are congenital in origin and incidental findings during investigations for unrelated conditions. Histologically, the cysts may be composed of various tissues, including bronchogenic, pericardial, thymic, enteric, Müllerian, lymphatic, and parathyroid types. Mediastinal cysts typically demonstrate a benign clinical course and patients are cured after complete surgical resection. In this review, the embryogenesis, clinical, radiologic, and pathologic characteristics of non-neoplastic mediastinal cysts are examined with discussion of the role of immunohistochemistry and the most pertinent differential diagnosis.

A Giant Thymic Cyst Accompanied by Acute Mediastinitis.

We encountered a rare case of thymic cyst accompanied by mediastinitis. A 39-year-old Japanese male presented with fever and chest pain. The chest CT revealed a mass composed of a lobular cystic lesion with inflammation, suggesting the onset of mediastinitis. A definitive histological diagnosis was not obtained, and we performed a thymectomy. Pathologically, the thymic cyst was accompanied by multiple cavities, mimicking thymic cysts, caused by the inflammatory abscess. The surrounding adipose tissue showed inflammatory cell infiltrations with chronic fibrosis. These findings indicate that clinicians should be aware that thymic cysts may cause severe mediastinitis.

A rare cause of Horner's syndrome: cervicothoracic spinal root cysts.

OBJECTION: We herein report cervicothoracic spinal root cysts as a rare cause of Horner's syndrome. CASE REPORT: A 62-year-old woman was admitted to our neuro-ophthalmology clinic complaining of drooping of her right upper eyelid. The history, physical examination, and laboratory tests were normal. The extraocular movements were full. The right eyelid was ptotic and the right pupil was smaller than the left. Right Horner's syndrome was diagnosed by the neuro-ophthalmologic examination and pharmacological tests. Cervical magnetic resonance imaging showed multiple spinal nerve root cysts between C7 and T1 segments of the spinal cord. CONCLUSION: This report showed for the first time that cervicothoracic spinal root cysts could cause Horner's syndrome and should be kept in mind in performing neuroimaging studies.

Pericardial Cysts: a Contemporary Comprehensive Review.

PURPOSE OF REVIEW: This is an in-depth review on the etiology, clinical manifestation, differential diagnosis, diagnostic modalities, complications, and management of pericardial cysts (PCs). RECENT FINDINGS: PCs are the third most common type of mediastinal masses and are usually identified incidentally by chest x-ray (CXR) or transthoracic echocardiography (TTE). Although most PCs are asymptomatic, they might lead to serious complications such as cardiac tamponade. Diagnosis is confirmed by cardiac computed tomography or cardiac magnetic resonance. Cysts need to be followed by imaging every 1 to 2 years; however, a recent report suggested less frequent follow-up. Most cases resolve spontaneously, but if needed, aspiration or surgical resection can be done. PCs are rare entities and are usually detected incidentally after CXR or TTE. Providers should be aware of this condition since it could potentially lead to serious complications.

SMARCB-1 deficient squamous cell carcinoma of a mediastinal cyst.

SMARCB1-deficiency has been found in a variety of tumors. Here, we report a SMARCB1-deficient squamous cell carcinoma of a mediastinal cyst. A 53-year-old man was diagnosed with a cyst of the pericardial region in his twenties. As a symptom at this time, he complained of severe pain and dyspnea in the right chest. Following investigation using imaging and histological examination of the biopsy specimen, he was diagnosed with a SMARCB1 deficient malignant neoplasm. As tumor cells showed positive immunostaining for p40 and CK5/6, the immunophenotype of the tumor was consistent with squamous cell carcinoma (SCC). The patient died six months after initial presentation. The autopsy showed the most part of the tumor with anaplastic cytomorphology, loss of SMARCB1, diffusely positive immunostaining for pancytokeratin, and negative immunostaining for p40 and CK5/6. To our knowledge, this is the first report of SMARCB1-deficient SCC of mediastinal cyst.

Ectopic cervical thymic cyst in a seven year old: a diagnostic challenge.

Cervical thymus cyst is a rare entity and resembles lymphangioma or branchial cleft cyst therefore, presents as a diagnostic challenge. It has a slight male predominance and presents on the left side of the neck in up to 70% of cases. It is a painless mass that progressively increases. We present a case of a seven year old child with a right sided neck swelling that would increase on phonation therefore, adding to the complexity of the case. Surgical excision was performed and final histopathology revealed an ectopic thymic cyst.

[True thymic hyperplasia : Differential diagnosis of thymic mass lesions in neonates and children]. / "Echte Thymushyperplasie" : Differenzialdiagnose der Thymusvergrößerung bei Säuglingen und Kindern.

Reactive and neoplastic thymic pathologies are the main considerations in the case of masses in the anterior and middle part of the mediastinum, while neurogenic tumors are predominant in the posterior mediastinum (which are not dealt with here). In neonates and infants, the commonest pathologies in the anterior mediastinum comprise germ cell tumors (mainly teratomas), congenital thymic cysts and true thymic hyperplasia (TTH). In toddlers, teratomas, yolk sac tumors and cysts predominate. In children over 5 years of age, lymphomas are the commonest mass lesions whereas thymomas and thymic carcinomas are rare. In addition, inflammation-linked hyperplasia in myasthenia gravis and rebound thymic hyperplasia after chemotherapy must be considered. Although rare at all ages, sarcomas must be considered in the differential diagnosis from birth onwards and throughout adolescence. Based on the report of a rare case of recurrent TTH, the differential diagnosis of this benign but potentially life-threatening condition is discussed.

A Mullerian Cyst Resected From the Posterior Mediastinum.

Differential diagnoses of mediastinal masses are often based on the anatomic locations. Traditionally the posterior mediastinum has been home to esophageal and neurogenic cysts, but a new entity has been found to be prevalent since its initial report in 2005: the Müllerian cyst. We present a 49-year-old with history of cough who was found to have such a mass. We will discuss the surgical outcome and the details of this interesting entity. The literature pertinent to this type of cyst will be evaluated. In all cases reported, the literature demonstrates that surgical removal results in uneventful follow-up with no evidence of malignancy or cyst recurrence.

[Two Surgical Cases of Müllerian Cyst Arising From the Posterior Mediastinum].

We experienced 2 cases of Müllerian cyst. Case 1 was a 48-year-old woman with a paravertebral cystic tumor. The tumor grew from 23 to 31 mm in diameter for the 3 years. She underwent video-assisted thoracic surgery(VATS) for the excision of the tumor. Case 2 was a 40-year-old woman with a paravertebral cystic tumor, who underwent VATS. The Histological finding showed that the tumors of both cases were the cysts lined by non-stratified cuboidal to columnar epithelium and epithelial cells were positive in the nucleus with estrogen receptor immunohistochemically. The resected cysts were finally diagnosed as Müllerian cyst. Twenty four published cases of Müllerian cyst were reported before, including symptomatic and growing cases. There were some reports of malignant transformation in cases of pelvic origin.

Convex-probe Endobronchial Ultrasound: A Decade of Progress.

Ever since the invention of the flexible bronchoscope, perhaps no other innovation in the field of interventional pulmonology has caused so much excitement the world over, as the convex probe endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA). While it took over a decade from 1992 to 2004 for the radial EBUS to evolve into the commercial convex probe EBUS scope, another exciting decade has gone by with the technology being thoroughly researched and appraised. The current evidence suggests that EBUS-TBNA can replace mediastinoscopy as the first investigation in the mediastinal staging of lung cancer. The use of EBUS-TBNA has been extended to several other areas including the diagnosis of undefined mediastinal lymphadenopathy, evaluation of intra-parenchymal lesions and others. In fact, EBUS-TBNA is the preferred modality for accessing mediastinal lesions in contact with the airways. The procedure not only has a high diagnostic efficiency (80%-90% for most indications) but is also safe compared to alternative options, such as image-guided fine needle aspiration and mediastinoscopy in the diagnosis of mediastinal lymphadenopathy. Apart from the traditional use of EBUS to perform TBNA, the last decade has seen the evolution of its transoesophageal use, development of novel EBUS-TBNA needles to obtain better histological specimens and a smaller EBUS scope. This review summarises the developments made in this field over the years since its inception.

[Non-neoplastic lesions of the mediastinum]. / Nichtneoplastische Läsionen des Mediastinums.

The mediastinum is a complex body region of limited space but containing numerous organs of different embryonic origins. A variety of lesions that are difficult to distinguish from each other can occur here. Non-neoplastic lesions of the mediastinum represent important differential diagnostic pitfalls to mediastinal tumors, clinically, radiologically and histopathologically. It is important to bear these lesions in mind and to adequately verify or exclude them before starting further differential diagnostic considerations on mediastinal neoplasms. The most common non-neoplastic lesions in this region include cysts and lymphadenopathies. Mediastinal cysts result from abnormal events in the branching of the tracheobronchial tree, the pharyngeal pouches, the primary intestines, the pleuropericardial membranes and the brain meninges or are complications of inflammatory and hydrostatic processes. The histogenesis of the lining epithelium and the cyst wall structure are decisive for the exact classification. The histopathologically most prevalent patterns of mediastinal lymphadenopathies are those accompanied by increased histiocytes and Castleman's disease. Sclerosis is a non-specific reaction pattern of the mediastinum and can be associated with many processes; therefore, when establishing the diagnosis of sclerosing mediastinitis, several differential diagnoses have to be excluded. Simple thymic hyperplasia can be accompanied by considerable increase in organ size with severe local symptoms, while follicular thymic hyperplasia is often associated with myasthenia gravis and represents the most common findings in non-thymoma thymectomy specimens.

Conditioned deletion of ephrinB1 and/or ephrinB2 in either thymocytes or thymic epithelial cells alters the organization of thymic medulla and favors the appearance of thymic epithelial cysts.

Our understanding about medullary compartment, its niches composition and formation is still limited. Previous studies using EphB2 and/or EphB3 knockout mice showed an abnormal thymic development that affects mainly to the epithelial component, including the cortex/medulla distribution, thymic epithelial cell (TEC) morphology and different epithelial-specific marker expression. We have already demonstrated that the lack of ephrinB1 and/or ephrinB2, either on thymocytes or on TECs, alters the cell intermingling processes necessary for thymus organization and affect cortical TEC subpopulations. In the present work, we have used the Cre-LoxP model to selectively delete ephrinB1 and/or ephrinB2 in thymocytes (EfnB1(thy/thy), EfnB2(thy/thy), EfnB1(thy/thy)EfnB2(thy/thy) mice) or TECs (EfnB1(tec/tec), EfnB2(tec/tec), EfnB1(tec/tec)EfnB2(tec/tec) mice) and have analyzed their role on the medullary compartment. In all the studied mutants, medullary areas are smaller and more compact than in the wt thymuses. In most of them, we observe abundant big cysts and a higher proportion of UEA(hi)MTS10(-) cells than in wt mice, which are often forming small cysts. On EfnB1(tec/tec)EfnB2(tec/tec), changes affecting organ size and medullary compartment start at perinatal stage. Our data shed some light on knowledge about wt medulla histological structure and cysts meaning and formation process and on the role played by ephrinB in them.

A case of giant mediastinal cyst initially detected and diagnosed by echocardiography.

Mediastinal cysts are a group of benign mediastinal lesions, and their diagnoses are primarily depended on x-ray and computed tomography. The development of ultrasound instruments and inspection techniques in recent years has led to the ability to use transthoracic echocardiography to clearly display structures surrounding the heart according to the dark fluid space (blood) of the atrium, ventricles, and large vessels as an acoustic window. This technique offers improved detection rates of mediastinal lesions. We report a case of a mediastinal cyst that was first detected and diagnosed on thoracic echocardiography examination and then confirmed by thoracoscopic surgery and pathological analysis.