Middle mediastinal lesions: imaging findings and pathologic correlation

Epicardial carvernous hemangioma: The diagnostic challenge of a middle mediastinal mass

Primary tumors in the middle mediastinum are rare and pose diagnostic challenges. Lymphomas, mediastinal cysts and thymomas most frequently affect this anatomic area. Primary cardiac tumors are rare and constitute a differential diagnosis for the inferior middle mediastinum. Surgical exploration and resection is often mandatory in order to make a definitive diagnosis. Here, we report the case of a 69 year-old women who presented with persistent dyspnea. A complete preoperative workup revealed a large tissular mass adjacent to the right atrium. A diagnosis of a typical epicardial cavernous hemangioma was made following surgical resection.

Schwannoma arising in mediastinal lymph node diagnosed by endobronchial ultrasound

Schwannoma is a peripheral nerve sheath tumour that largely originates from the posterior mediastinum. Schwannoma arising in mediastinal lymph node is extremely rare. A 53-year-old female was referred to our hospital for the evaluation of enlarged mediastinal lymph node. Computed tomography scan revealed a non-enhancing soft tissue mass at Rt. paratracheal area. Endobronchial ultrasound showed a well-defined round-shaped lymph node and transbronchial needle aspiration was performed from this lymph node. Pathologic findings revealed spindle cells with strong S100 positivity. Complete surgical excision was done. We report a rare case of schwannoma arising in mediastinal lymph node diagnosed by endobronchial ultrasound.

Angiographic embolization followed by piecemeal resection of giant posterior mediastinal schwannoma: Case report and concise review

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Radiographic assessment of spinal cord involvement is essential.

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Histology is necessary to establish etiology, prognosis, and treatment plan.

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Large tumors may require posterolateral thoracotomy and piecemeal resection.

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Preoperative angiography may identify arteries shared by the tumor and spinal cord.

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Preoperative angioembolization may reduce tumor vascularity and operative blood loss.

Introduction: Posterior mediastinal masses present unique diagnostic and therapeutic challenges, particularly when large highly vascularized tumors extend toward or emanate from the spinal cord. The rare nature of these tumors precludes the development of standardized management algorithms, underscoring the importance of case reports.

Presentation of case: A 57 year old female presented with exertional dyspnea and right chest pressure. Chest radiography followed by computed tomography (CT) scan demonstrated a 13 cm posterior mediastinal mass involving the T7 vertebral body. CT-guided percutaneous biopsy confirmed benign schwannoma. During open exploration, the tumor bled easily with contact. Angiography with intercostal arterial embolization decreased tumor vascularity while preserving spinal cord perfusion. Subsequent piecemeal resection facilitated exposure of the tumor base and complete resection. Postoperative recovery was uneventful.

Discussion: Neurogenic tumors are most commonly located in the posterior mediastinum. When untreated, schwannomas continue to grow, and will inevitably cause compressive symptoms if given sufficient time. Therefore, resection is recommended. This may be performed thoracoscopically in select patients with small tumors, avoiding the morbidity of a thoracotomy incision.

Conclusion: Large posterior mediastinal schwannomas require posterolateral thoracotomy and resection. Preoperative angiography helps identify arteries shared by the tumor and the spinal cord, and embolization may reduce tumor vascularity and operative blood loss thereby permitting safer resection.

Middle mediastinal schwannoma concealed by asthma and GORD

Neurogenic tumours of the mediastinum in adults occur most often at the posterior mediastinum, majority of which are benign of nerve sheath in origin. A 72-year-old woman, known asthmatic, presented with chronic symptoms of hoarseness, dysphagia, chest heaviness, easy fatigability, cough, epigastric pain, feeling of abdominal fullness and choking with food intake and at a supine position. Treated for other disorders, routine chest X-ray incidentally found a homogenous convex radiodensity at the right paratracheal area; mass which was also observed with CT and 18F-fludeoxyglucose-positron emission tomography/CT scan studies. Mediastinoscopy with biopsy showed spindle to plump cells with strong S100 positivity. Thoracoscopic surgery done to completely excise the mass found it to be benign schwannoma.

A diagnostic approach to the mediastinal masses

Background

Multiple different types of mediastinal masses may be encountered on imaging techniques in symptomatic or asymptomatic patients. The location and composition of these lesions are critical to narrowing the differential diagnosis.

Methods

Radiological compartmentalisation of the mediastinum helps in focusing the diagnosis of masses on the basis of their site. Some diseases, however, do not occur exclusively in any specific compartment and can spread from one compartment to another.

Results

Tissular components of the mass, the degree of vascularisation and the relationships with mediastinal structures assessed by computed tomography (CT) or magnetic resonance imaging (MRI) are a leading edge of the radiological diagnosis. Special applications at MRI have been developed over the recent years in order to identify accurately tissular components of the mediastinal masses. The likelihood of malignancy of the mediastinal masses is influenced by the symptomatology and the age of the patient. This article reviews the most commonly encountered mediastinal masses considering clinical history and manifestations, anatomical position and certain details seen on different imaging modalities that allow correct diagnosis in many cases.

Conclusion

Familiarity with the radiological features of mediastinal masses facilitates accurate diagnosis, differentiation from other mediastinic processes and, thus, optimal patient treatment.

Teaching Points

• CT and MRI are important for the diagnosis of mediastinal masses.

• The location and tissue characteristics on imaging studies are critical to narrow down the differential diagnosis of mediastinal masses.

• Symptomatology and patient age affect the likelihood of malignancy.

Tumors of the mediastinum and chest wall

Primary tumors of the mediastinum and chest wall comprise a diverse group of conditions with a wide range of presentations. A thorough knowledge of thoracic anatomy is essential for appropriate diagnosis and treatment. Given their proximity to critical structures, treatment of these tumors is often challenging. Although surgery is the mainstay of therapy for most mediastinal and chest wall tumors, a multidisciplinary approach is valuable in many cases.