Is chest CT sufficient for follow-up of primary mediastinal B-cell lymphoma in remission?

Update in diagnostic imaging of the thymus and anterior mediastinal masses

Anterior mediastinal masses include a wide spectrum of malignant and benign pathologies with a large percentage represented by thymic lesions. Distinguishing these masses on diagnostic imaging is fundamental to guide the proper management for each patient. This review illustrates possibilities and limits of different imaging modalities to diagnose a lesion of the anterior mediastinum with particular attention to thymic disease.

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.

Evaluation of the response to treatment of solid tumours - a consensus statement of the International Cancer Imaging Society

New guidelines to evaluate the response to treatment in solid tumors using imaging techniques have major limitations and important implications for radiological workload. This consensus statement from the International Cancer Imaging Society (ICIS) reviews the RECIST criteria and addresses several challenges regarding tumour measurement. Recommendations are made regarding tumour measurement and other issues are raised. The growing need to introduce a multimodality approach to monitoring response is recognized. ICIS welcomes a dialogue with the authors of RECIST to address issues raised in this review.

Post-treatment surveillance of patients with lymphoma treated with curative intent

Hodgkin's lymphoma and aggressive non-Hodgkin's lymphoma (NHL) are common, potentially curable cancers. Despite modern therapy, many patients will relapse. A number of relapsing patients may be cured with subsequent treatment, including high-dose chemotherapy. Risk of relapse after potentially curative therapy is greatest in the first 2 years, and post-treatment surveillance should be concentrated during this time. Most patients will present with symptoms or physical findings at relapse. Physicians and patients should be aware of common symptoms associated with relapse, and laboratory and radiological testing should be used to assess such concerns.

Extranodal imaging manifestations of non-Hodgkin's lymphoma

A series of imaging features of extranodal, multi-systemic involvements in Non-Hodgkin's lymphoma (NHL) were investigated. The clinical data and imaging findings of 16 patients with pathologically proved NHL were retrospectively analyzed. The related literatures were reviewed. Of the 16 cases of NHL, skeletal involvement was found in 4, nasal cavity and nasal sinuses were involved in 4, too. Lesion in the thorax was seen in 3 patients, hepatic involvement occurred in one case, cerebral ventricle was affected in 3 cases, mesentery was involved in one case. Even though extranodal involvement of NHL exhibited extremely variable patterns, there were some relatively typical imaging findings. Emphasized in this report were the relatively specific imaging manifestations of different systems, which may mimic infectious or other neoplasms of different sites. The importance of imaging studies lies in the availability for diagnosis, staging and follow-up of NHL. Combined with the clinical and other related information, the diagnostic accuracy can be further improved, thus, providing reliable evidence in guiding clinical management.