Abdominal Manifestations of Lymphoma: Spectrum of Imaging Features

Non-Hodgkin and Hodgkin lymphomas frequently involve many structures in the abdomen and pelvis. Extranodal disease is more common with Non-Hodgkin’s lymphoma than with Hodgkin's lymphoma. Though it may be part of a systemic lymphoma, single onset of nodal lymphoma is not rare. Extranodal lymphoma has been described in virtually every organ and tissue. In decreasing order of frequency, the spleen, liver, gastrointestinal tract, pancreas, abdominal wall, genitourinary tract, adrenal, peritoneal cavity, and biliary tract are involved. The purpose of this review is to discuss and illustrate the spectrum of appearances of nodal and extranodal lymphomas, including AIDS-related lymphomas, in the abdominopelvic region using a multimodality approach, especially cross-sectional imaging techniques. The most common radiologic patterns of involvement are illustrated. Familiarity with the imaging manifestations that are diagnostically specific for lymphoma is important because imaging plays an important role in the noninvasive management of disease. 1. Introduction The malignant lymphomas, Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL), comprise approximately 5% to 6% of all malignancies [1]. Lymphomas frequently involve nodal and extranodal structures in the abdomen and pelvis [2, 3]. HD is usually almost entirely confined to the lymph nodes [4, 5]. Extranodal lymphoma occurs in about 40% of patients and has been described in virtually every organ and tissue. In decreasing order of frequency, the spleen, liver, gastrointestinal tract, pancreas, abdominal wall, genitourinary tract, adrenal, peritoneal cavity, and biliary tract are involved [2]. The purpose of this review is to discuss and illustrate the spectrum of appearances of nodal and extranodal lymphomas, including AIDS-related lymphomas, in the abdominopelvic region using a multimodality approach, especially cross-sectional imaging techniques. 2. Nodal Disease Most normal lymph nodes (LN) are about 1？cm in size; however that size varies depending on their location [6]. Nodal disease can be solitary or more commonly multiple [3]. Solitary mass type of nodal lymphoma includes singular enlarged LN and fusion of multiple enlarged LN (Figure 1). CT usually shows a huge round mass or a lobular homogeneous density mass with uniform enhancement [3]. Figure 1: CT of the abdomen demonstrates lymph nodes involving mesenteric vessels (sandwich sign) anterior to aorta and inferior to vena cava in a patient with lymphoma (arrows). Multiple-nodular type of lymphoma, the most frequently seen, can be characterized by