B-Cell Lymphoma with Gastric and Pancreatic Invasion
Publication Date: 2022-09-23
History
40-year-old male with 1 month history of abdominal pain
Findings
1. Axial CT image after injection of intravenous contrast demonstrating a large posterior mediastinal lymph node mass located medial to the esophagus and aorta.
2. Axial CT image after injection of intravenous contrast demonstrating a large confluent celiac axis lymph node mass with invasion of the lesser curvature gastric wall.
3. Axial CT image after injection of intravenous contrast demonstrating a hypo-enhancing infiltrative pancreatic tail mass.
4. Axial T2 weighted fast spin-echo fat saturated image demonstrating the infiltrative pancreatic tail mass, which is hyperintense with respect to normal pancreas. Note that there is preservation of the internal ductal architecture.
5. Axial T2 weighted fast spin-echo fat saturated image demonstrating the large confluent celiac axis lymph node mass with invasion of the lesser curvature gastric wall.
6. Post contrast T1 weighted fat saturated image reveals the infiltrative pancreatic tail mass, which is hypo enhancing compared to the remainder of the pancreas.
7. Diffusion-weighted image (B=800) showing increased signal indicative of restricted diffusion in the celiac lymph node mass. Restricted diffusion is common in lymphoma and other tumors with a high nucleus-to-cytoplasm ratio.
Diagnosis
B-Cell lymphoma
Discussion
Lymphoma describes a group of hematologic malignancies with lymphoid or myeloid origin, and is broadly separated into Non-Hodgkin’s lymphoma (NHL) vs. Hodgkin’s lymphoma (HL). The risk for NHL increases with age, with a median age of 65 years, while HL has bimodal peaks of 20-29 years and >55 years. Lymphoma is the 5th most common cancer in the United States. Compromised immunity greatly increases the risk for NHL. The most common presenting symptoms include abdominal pain, nausea, vomiting, weight loss, fever, organomegaly, and palpable adenopathy. Common laboratory findings include cytopenias (anemia, leukopenia, and/or thrombocytopenia), and elevated serum levels of LDH, calcium, and uric acid. Differential diagnosis to consider would include sarcoidosis, infection, and primary visceral organ malignancy.
As the name would suggest, lymphoma involves lymph nodes, and the most common imaging finding in lymphoma is node enlargement. However, lymph node size is not a reliable differentiator for lymphoma vs. other etiologies, as enlargement is not specific to lymphoma. Additionally, normal-sized nodes are still malignant with high frequency, and large nodes are still benign with high frequency. HL typically spreads in a contiguous pattern along nodes, while non-contiguous groups are often involved in NHL. A “sandwich sign” may be seen on CT, which describes a large conglomerate nodal mass surrounding mesenteric blood vessels, which may be totally encased, but typically without vessel narrowing or occlusion. Both NHL and HL are staged using the Lugano staging system.
Lymphomas, especially NHL, may also involve organs other than lymph nodes, which are known as “extra-nodal sites.” The most common extra-nodal site for NHL is the GI tract, with most of these cases being secondary to widespread disease, as opposed to primary GI tract lymphoma. The GI tract is involved in over 50% of disseminated NHL cases, and the stomach is the most common GI organ involved. The second most common GI tract lymphoma is mucosa-associated lymphoid tissue (MALT). GI tract lymphomas typically exhibit one of four major patterns, or some combination of them. These include (1) infiltrative pattern, which involves circumferential wall thickening of the organ. (2) Ulcerative pattern, which are frequently large and cavitated. (3) Polypoid pattern, which involves an intraluminal extension of the mass. (4) Nodular pattern, which involves multiple submucosal lesions.
Regarding pancreatic involvement, primary pancreatic lymphoma is quite rare, and again is typically secondary to widespread disease. It may be visualized as a discrete mass that is infiltrative and hypo-enhancing on CT. This may lead to misidentification as adenocarcinoma, however lymphoma importantly involves preservation of pancreatic duct integrity and no glandular atrophy. Blood vessels also course through the mass without narrowing or occlusion. Multiple masses may also be seen. Diffuse infiltration may result in glandular enlargement and be mistaken for pancreatitis, but lymphoma does not involve peri-pancreatic inflammatory changes. Discussion:
Gastric lymphoma is an uncommon type of gastric malignancy, but is the most common lymphoma involving the GI tract, typically affecting middle-age and older adults.(1) There is a spectrum of histological presentation, but is generally divided into two main types: low-grade mucosa-associated lymphoid tissue (MALT) lymphoma and high-grade non-Hodgkin lymphoma most commonly diffuse large B-cell lymphoma (DLBCL).(2) MALT lymphomas are commonly associated with H. pylori infection. The most common presentation for both types is very non-specific, including abdominal pain, weight loss, or painless abdominal mass. However, patients can be asymptomatic until late in the disease progression.(1)
Due to their association with H. pylori infection, the majority of gastric MALT lymphomas can be treated and cured with H. pylori eradication therapy.(3) Therefore, gastric MALT lymphomas generally have a better prognosis than primary or secondary gastric non-Hodgkin lymphomas. Treatment of non-MALT gastric lymphomas is complex but typically requires chemotherapy, radiation, and uncommonly surgical intervention.(4)
Prognosis and treatment vary by type and stage. Imaging plays a major role in initial diagnosis, but tissue or marrow biopsy is required for final diagnosis. Imaging is also important for assessing response to treatment, surveillance for recurrence, and assessing potential complications.
References: 1. Younan G: Pancreas solid tumors. Surg Clin North Am. 100(3):565-80, 2020 2. Chang ST et al: Imaging of primary gastrointestinal lymphoma. Semin Ultrasound CT MR. 34(6):558-65, 2013 3. Paes FM et al: FDG PET/CT of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease. Radiographics. 30(1):269-91, 2010 4. Chua SC et al: Imaging features of primary extranodal lymphomas. Clin Radiol. 64(6):574-88, 2009 5. Lee WK et al: Abdominal manifestations of extranodal lymphoma: spectrum of imaging findings. AJR Am J Roentgenol. 191(1):198-206, 2008
1. Juárez-Salcedo LM et al: Primary gastric lymphoma, epidemiology, clinical diagnosis, and treatment. cancer control. 25(1):1073274818778256, 2018 2. Burke JS: Lymphoproliferative disorders of the gastrointestinal tract: a review and pragmatic guide to diagnosis. Arch Pathol Lab Med. 135(10):1283-97, 2011 3. Santacroce L et al: Helicobacter pylori infection and gastric MALTomas: an up-to-date and therapy highlight. Clin Ter. 159(6):457-62, 2008 4. Ikoma N et al: Multimodality treatment of gastric lymphoma. Surg Clin North Am. 97(2):405-20, 2017
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