Diagnostic approach to mediastinal masses

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

ACR Appropriateness Criteria® Imaging of Mediastinal Masses

Mediastinal masses can present with symptoms, signs, and syndromes or incidentally. Selecting the appropriate diagnostic imaging study for mediastinal mass evaluation requires awareness of the strengths and weaknesses of the various imaging modalities with regard to tissue characterization, soft tissue contrast, and surveillance. This publication expounds on the differences between chest radiography, CT, PET/CT, ultrasound, and MRI in terms of their ability to decipher and surveil mediastinal masses. Making the optimal imaging choice can yield diagnostic specificity, avert unnecessary biopsy and surgery, guide the interventionist when necessary, and serve as a means of surveillance for probably benign, but indeterminate mediastinal masses. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Anterior Mediastinal Mass Causing Intermittent Atrial Fibrillation

Mediastinal masses are a rare finding in the emergency department and typically present with vague chest complaints such as chest discomfort, chest pain, or dyspnea. Rarely do these tumors present with dysrhythmias, and when dysrhythmias are present, they typically arise secondary to endocrine or metabolic effects exerted by the tumor. Here we report a case of a patient who presented to the emergency department with atrial fibrillation with rapid ventricular response, concomitant with a history of recurrent palpitations that were previously aborted with self-induced vagal maneuvers. Upon further investigation, the patient had an anterior mediastinal mass, diagnosed as a thymoma, suspected to be contributing to his presenting dysrhythmia through mass effect.

Extramedullary haematopoiesis presented as intrathoracic tumour in a patient with alpha-thalassaemia

The authors report a case of extramedullary haematopoiesis (EMH) presenting as an intrathoracic tumour in a patient with alpha-thalassaemia. CT scan and MRI of the chest were obtained and followed by tumour excision. Compared to beta-thalassaemia, only two cases of EMH in patients with alpha-thalassaemia have been described in the literature. A possible reason for this disparity is discussed.

Lines and stripes: where did they go?--From conventional radiography to CT

Frontal and lateral radiography has traditionally been used to evaluate the chest, although computed tomography (CT) and high-resolution CT are increasingly being used as an adjunct to conventional radiography for the evaluation of parenchymal and mediastinal disease. Nevertheless, radiography remains a very important modality in this context, and use of chest radiography alone can provide a vast amount of useful information. This information is derived from the configurations and interrelationships of the anatomic structures in the lung, mediastinum, and pleura and forms the basis of the "lines and stripes" concept, which plays a valuable role in establishing a diagnosis before proceeding to CT. The inability to recognize that a chest radiograph is abnormal owing to displacement of one of these lines or stripes may lead to failure to request a potentially valuable CT examination. Radiologists must be familiar with the anatomic basis of these mediastinal lines and stripes and be able to recognize their normal and abnormal appearances. In this way, they can develop an appropriate differential diagnosis prior to obtaining additional information with chest CT.

Intrathoracic Masses Due to Extramedullary Hematopoiesis

Extramedullary hematopoiesis often occurs in hemoglobinopathies, hemolytic anemias, leukemias, lymphomas, and myeloproliferative disorders. Liver, spleen, and lymph nodes are frequently involved. However, extramedullary hematopoiesis may also develop in other sites such as thymus, kidney, retroperitoneum, and paravertebral areas of the thorax. Extramedullary hematopoietic masses are often microscopic and asymptomatic, but sometimes they lead to tumor-like masses. We describe massive intrathoracic extramedullary hematopoiesis in a 41-year-old man with compound heterozygosis for beta-thalassemia and sickle cell anemia and functional asplenia. We also describe a 39-year-old man with beta-thalassemia intermedia, who was initially diagnosed as having tumor masses, but was later proved, by magnetic resonance imaging, to have extramedullary erythropoietic tissue. These observations provide further support to include extramedullary hematopoiesis among the differential diagnosis of tumor-like masses in patients with hematologic diseases.

Diagnosis of mediastinal masses and principles of surgical tactics and technique for their treatment

The diagnosis of a mediastinal mass is first based on clinical features, supplemented by epidemiological data and laboratory results providing information on the nature and localization of the mass. The diagnosis is then defined further on the basis of imaging studies. The first examinations required are standard radiographs, ultrasound scan or computed tomography scan and occasionally magnetic resonance imaging (MRI), angiography, and scintigraphy. These studies are followed by a thoracoscopy, mediastinoscopy, and the necessary biopsy techniques. Finally, the author describes the general principles of surgical tactics and techniques that generally lead to a total regression of the disease.