180 lines
13 KiB
Markdown
180 lines
13 KiB
Markdown
---
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title: "Abdominal Lymph Nodes"
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docid: "3ca98d42-20ef-48fe-9265-ebfe570ba54b"
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authors:
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- key: "07469ec4-05aa-4d65-a788-08b4d64048af"
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value: "Jade Wong-You-Cheong, MBChB, MRCP, FRCR, FSRU, FSAR"
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breadcrumbs:
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-
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name: "Ultrasound"
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slug: "ultrasound"
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treeNodeId: "e7cdfeb1-bb55-4cca-9854-46cadee515d2"
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-
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name: "Anatomy"
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slug: "anatomy"
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treeNodeId: "d4765014-54f9-4477-8c9c-4b2ae0b82f24"
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-
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name: "Abdomen"
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slug: "abdomen"
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treeNodeId: "1e981810-ddca-4af9-82b9-38d5fdecad76"
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-
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name: "Abdominal Lymph Nodes"
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slug: "abdominal-lymph-nodes"
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treeNodeId: null
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category: "Ultrasound"
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documentVersionId: "43db6bf2-6355-41b6-9d98-6af776f561f7"
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imageCount: 7
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lastUpdated: "05/03/21"
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pageDescription: "Abdominal Lymph Nodes"
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pageKeywords: "Ultrasound, Anatomy, Abdomen, Abdominal Lymph Nodes"
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pageTitle: "Abdominal Lymph Nodes | STATdx"
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enhancedTitle: "Abdominal Lymph Nodes"
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type: "ANATOMY"
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references: true
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breadcrumbs:
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- "Ultrasound"
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- "Anatomy"
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- "Abdomen"
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- "Abdominal Lymph Nodes"
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---
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# GROSS ANATOMY
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- ## Overview
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- Major lymphatic vessels and nodal chains lie along major blood vessels [aorta, inferior vena cava (IVC), iliac]
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- Lymph nodes carry same name as vessel they accompany
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- Lymph from alimentary tract, liver, spleen, and pancreas passes along celiac, superior mesenteric chains to nodes
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- Efferent vessels from alimentary nodes form intestinal lymphatic trunks
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- Cisterna chyli (chyle cistern)
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- Formed by confluence of intestinal lymphatic trunks and right and left lumbar lymphatic trunks, which receive lymph from nonalimentary viscera, abdominal wall, and lower extremities
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- May be discrete sac or plexiform convergence
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- Thoracic duct: Inferior extent is chyle cistern at L1-2 level
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- Formed by convergence of main lymphatic ducts of abdomen
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- Ascends through aortic hiatus in diaphragm to enter posterior mediastinum
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- Ends by entering junction of left subclavian and internal jugular veins
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- Lymphatic system drains surplus fluid from extracellular spaces and returns it to bloodstream
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- Important function in defense against infection, inflammation, and tumor via lymphoid tissue present in lymph nodes, gut wall, spleen, and thymus
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- Absorbs and transports dietary lipids from intestine to thoracic duct and bloodstream
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- Lymph nodes
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- Composed of cortex and medulla
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- Invested in fibrous capsule, which extends into nodal parenchyma to form trabeculae
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- Internal honeycomb structure filled with lymphocytes that collect and destroy pathogens
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- Hilum: In concave side, with artery and vein, surrounded by fat
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- ## Abdominopelvic Nodes
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- Preaortic nodes
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- Celiac nodes: Drainage from gastric nodes, hepatic nodes, and pancreaticosplenic nodes
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- Superior and inferior mesenteric nodes: Drainage from mesenteric nodes
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- Lateral aortic nodes (paraaortic)
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- Drainage from kidneys, adrenal glands, ureter, posterior abdominal wall, testes and ovary, uterus and fallopian tubes
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- Retroaortic nodes
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- Drainage from posterior abdominal wall
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- External iliac nodes
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- Primary drainage from inguinal nodes
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- Flow into common iliac nodes
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- Internal iliac nodes
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- Drainage from inferior pelvic viscera, deep perineum, and gluteal region
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- Flow into common iliac nodes
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- Common iliac nodes
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- Drainage from external iliac, internal iliac, and sacral nodes
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- Flow into lumbar (lateral aortic) chain of nodes
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- Superficial inguinal nodes
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- In superficial fascia parallel to inguinal ligament, along cephalad portion of greater saphenous vein
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- Receive lymphatic drainage from superficial lower extremity, superficial abdominal wall, and perineum
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- Flow into deep inguinal and external iliac nodes
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- Deep inguinal nodes
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- Along medial side of femoral vein, deep to fascia lata and inguinal ligament
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- Receive lymphatic drainage from superficial inguinal and popliteal nodes
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- Flow into external iliac nodes
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# IMAGING ANATOMY
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- ## Overview
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- CT is test of choice for cancer staging
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- May be supplemented by PET/CT or MR in select cancers
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- Ultrasound may be useful in children or thin adults
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- Normal nodes are elliptical with echogenic fatty hilum and uniform hypoechoic cortex
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- Normal lymph nodes rarely detected on abdominal ultrasound
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- Short-axis diameter > 10 mm typically considered enlarged, but normal diameter of lymph node varies depending on location
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- Retrocrural < 6 mm
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- Hepatogastric ligament < 8 mm, porta hepatis < 7 mm
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- Mesenteric < 5 mm
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- Inguinal < 15 mm
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# ANATOMY IMAGING ISSUES
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- ## Imaging Recommendations
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- Transducer: 2-5 MHz or 5-9 MHz for thinner patients
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- Patient examined in supine position with 6-8 hours of fasting to decrease bowel gas
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- Graded compression technique to clear overlying bowel loops
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# CLINICAL IMPLICATIONS
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- ## Clinical Importance
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- Nodal enlargement is nonspecific; may be neoplastic, inflammatory, or reactive
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- Normal-sized lymph nodes may harbor metastatic malignancy
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- Node morphology is more specific for pathology
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- Abnormal nodes have replacement or loss of fatty hilum
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- Look for central necrosis, cystic change, calcification or irregular margin, and location of nodes (if in drainage field of tumor)
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- Lymphoma
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- Multiple enlarged hypoechoic or anechoic nodes
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- Metastatic lymphadenopathy
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- More echogenic and heterogeneous nodes compared to lymphomatous nodes
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- Infectious/reactive lymphadenopathy
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- Nonspecific sonographic features
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- May contain necrotic centers in mycobacterial infection
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344781fd-34ab-4335-bb66-19706f7d2d68
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## References
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# Selected References
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1. [Koh DM et al: Cross-sectional imaging of nodal metastases in the abdomen and pelvis. Abdom Imaging. 31(6):632-43, 2006](http://www.ncbi.nlm.nih.gov/pubmed/?term=16897278%5Bpmid%5D)
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1. [Lucey BC et al: Mesenteric lymph nodes: detection and significance on MDCT. AJR Am J Roentgenol. 184(1):41-4, 2005](http://www.ncbi.nlm.nih.gov/pubmed/?term=15615948%5Bpmid%5D)
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## Images
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### Abdominal Lymph Nodes
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*Graphic shows that the major lymphatics and lymph nodes of the abdomen are located along, and share the same name as, the major blood vessels, such as the external iliac nodes, celiac, and superior mesenteric nodes. The paraaortic and paracaval nodes are also referred to as the lumbar nodes and receive afferents from the lower abdominal viscera, abdominal wall, and lower extremities; they are frequently involved in inflammatory and neoplastic processes. The lumbar trunks join with an intestinal trunk (at about the L1 level) to form the cisterna chyli, which may be a discrete sac or a plexiform convergence. The cisterna chyli and other major lymphatic trunks join to form the thoracic duct, which passes through the aortic hiatus to enter the mediastinum. After picking up additional lymphatic trunks within the thorax, the thoracic duct empties into the left subclavian or innominate vein.*
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*Graphic shows that the major lymphatics and lymph nodes of the abdomen are located along, and share the same name as, the major blood vessels, such as the external iliac nodes, celiac, and superior mesenteric nodes. The paraaortic and paracaval nodes are also referred to as the lumbar nodes and receive afferents from the lower abdominal viscera, abdominal wall, and lower extremities; they are frequently involved in inflammatory and neoplastic processes. The lumbar trunks join with an intestinal trunk (at about the L1 level) to form the cisterna chyli, which may be a discrete sac or a plexiform convergence. The cisterna chyli and other major lymphatic trunks join to form the thoracic duct, which passes through the aortic hiatus to enter the mediastinum. After picking up additional lymphatic trunks within the thorax, the thoracic duct empties into the left subclavian or innominate vein.*
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### Nonenlarged Nodes and Pathologic Nodes
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*Transverse ultrasound at the level of the pancreas and splenic vein shows a small interaortocaval node.*
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*Transverse ultrasound of the epigastric region shows an enlarged, hypoechoic, peripancreatic, lymph node anterior to the portal vein in a patient with hepatitis C. Normal-sized lymph nodes are rarely seen in adult abdominal ultrasound.*
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*Transverse ultrasound of the upper midline abdomen in a patient with lymphoma shows multiple abnormal enlarged, hypoechoic lymph nodes around the superior mesenteric artery.*
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### CT and Lymphangiogram
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*Axial CT shows a small benign interaortocaval lymph node.*
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*Coronal CT shows a row of small elliptical left paraaortic lymph nodes; the most inferior node has a clear fatty hilum. These were benign.*
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*Normal lymphatic channels and lymph nodes are best seen on a lymphangiogram performed with Lipiodol contrast. In this case, performed for chylous leak, normal pelvic and retroperitoneal nodes and lymphatics are opacified.*
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