Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Non-Hodgkin's Lymphoma(Diffuse Large B-cell Type)
- Radiologic Findings
- Figs 1. Chest PA radiograph shows a left paratracheal bulging mass. Fig 2-5. Contrast-enhanced chest CT scans show a homogenous lobulating anterior mediastinal mass. Note intraluminal partial thrombosis extending from the mass in the left innominate vein.
- Brief Review
- Malignant lymphoma that involves mainly or exclusively the mediastinum at initial presentation (primary mediastinal lymphoma) is a relatively common condition seen in patients of all ages. Most cases are due to 1 of 3 histologic subtypes: Hodgkin lymphoma, mediastinal diffuse large B-cell lymphoma, and precursor T-cell lymphoblastic lymphoma.
In these early reviewers, some tumors had initially been misdiagnosed as thymomas, seminomas, or anaplastic carcinomas, and considerable overlap of imaging findings between mediastinal lymphomas and other types of anterior mediastinal masses does exist. Masses typically exhibit homogenous soft-tissue attenuation, while large tumors may demonstrate heterogeneity with complex lo low attenuation representing necrosis, hemorrhage, and cystic degeneration, regardless of subtypes of mediastinal lymphoma.
The surface lobulation of the main mass is due to involvement of multiple nodes and coalescence, a finding most commonly noted in hodgkin’s lymphoma at CT followed by mediastinal diffuse large B-cell lymphoma. The presence of superior vena cava syndrome has been reported up to 35% of 20 mediastinal diffuse large B-cell lymphoma. Extrathoracic lymphadenopathy including superficial cervical, supraclavicular, submandibular, submental, parotid, mesenteric, and inguinal nodes, was seen in the majority of patients with T-cell lymphoblastic lymphoma in the present study. Another common finding in T-cell lymphoblastic lymphoma in the current study was the presence of splenomegaly, which was seen in 63% of cases.
Large-cell lymphomas elsewhere in the body occur as a median age of 52 years and show a 2:1 male to female predominance. Conversely, the median age of patients with primary mediastinal large B-cell lymphomas is the in the 30s. For this type of lymphoma, a female-to-male predominance of approximately 3:2 has been described. Mediastinal large B-cell lymphoma typically is initially confined to the mediastinum and contiguous nodal areas without showing extrathoracic disease at presentation. Mediastinal large B-cell lymphoma may present with hematogenous spread to parenchymal organs such as kidney, liver, ovary, adrenal gland, gastrointestinal tract, and central nervous system during disease progression or at recurrence.
- References
- 1. Shaffer K, Smith D, Kaplan W, et al. Primary mediastinal large-B-cell lymphoma: radiologic findings at presentation. AJR 1996; 167:425-430
2. Tateishi U, Muller NL, Johkoh T, et al. Primary mediastinal lymphoma: characteristic features of the various histological subtypes on CT. JCAT 2004;28:782-789
- Keywords
- Mediastinum, Lymphproliferative disorder, Lymphoma,