Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Primary mediastinal large B-cell lymphoma
- Radiologic Findings
- Fig 1. Chest PA shows mediastinal widening.
Fig 2-3. CT scans reveal about 55 mm-sized lobulated mass in right upper lobe with invasion to anterior mediastinum. The mass shows heterogeneous enhancement with internal low density. A few borderline-sized lymph nodes are also seen in anterior mediastinum.
Fig 4-5. In follow up CT scans after 2 month, the lobulated mass shows increased size with increased internal necrotic portion. Small amount of pericardial effusion also newly seen.
- Brief Review
- Lymphomas are responsible for approximately 15% of all primary mediastinal masses. Only 10% of lymphomas which involve the mediastinum are primary and the majority (~60%) are Hodgkin's lymphomas (HL).
Although HL and non-hodgkin’s lymphoma (NHL) may have overlapping imaging findings, HL is characterized by the presence of a discrete anterior mediastinal mass with a lobulated contour. The tumor most commonly demonstrates homogeneous soft-tissue attenuation, although large lymph node masses may demonstrate heterogeneity with complex low attenuation representing necrosis, hemorrhage, or cystic degeneration.
Lymph nodes involved in NHL tend to be larger as compared with those in HL and have a predilection for noncontiguous or hematogenous spread to thoracic and distant nodal and extranodal sites. Large B-cell lymphoma and lymphoblastic lymphoma are the most common subtypes, primarily involving the anterior mediastinum. Specifically, primary mediastinal large B-cell lymphomas usually present large and lobulated anterior mediastinal masses and occur predominantly in young adults, while also often directly invading adjacent structures. Low attenuation areas of necrosis within the mass were seen in 50% and calcification in 5%.
- Please refer to
Case 488, Case 492, Case 619, Case 894, Case 1019, -
- References
- 1. Duwe BV, Sterman DH, Musani AI. Tumors of the mediastinum. Chest. 2005;128 (4): 2893-909.
2. Bae YA, Lee KS. Cross-sectional evaluation of thoracic lymphoma. Radiol Clin North Am. 2008 Mar;46(2):253-64
- Keywords
- anterior mediastinum, Primary Pulmonary Lymphoma , B-cell lymphoma ,