Lymph node metastasis is the spread (

metastasis Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then ...

) of cancer cells into a lymph node. Lymph node metastasis is different from

malignant lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enla ...

. Lymphoma is a cancer ''of'' lymph node, rather than cancer ''in'' the lymph node, because lymphoma originates from the lymph node itself, instead of originating elsewhere (e.g., the breast or colon) and spreading to the lymph nodes.

Pathology

Generally, metastases form first in the lymph nodes that are closest to the

primary tumor A primary tumor is a tumor growing at the anatomical site where tumor progression began and proceeded to yield a cancerous mass. Most cancers develop at their primary site but then go on to metastasize or spread to other parts of the body. These fur ...

. This is because the

lymphatic fluid Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to ...

(lymph) of the cancerous organ or tissue flows first to these nearby lymph nodes. The tumor cells reach the lymph nodes via this lymphatic pathway, where they remain and proliferate. These spreading cancer cells grow in the lymph nodes, which causes the affected lymph nodes to get bigger. Lymphogenic metastasis is a type of regional metastases. This is in contrast to distant metastases, such as

bone metastases Bone metastasis, or osseous metastatic disease, is a category of cancer metastases that results from primary tumor invasion to bone. Bone-originating primary tumors such as osteosarcoma, chondrosarcoma, and Ewing's sarcoma are rare; the most common ...

, liver metastases or brain metastases, which could come from any part of the body. Tumor cells that grown in the lymph nodes can later detach from the lymph node metastases, enter the bloodstream, and lead to distant metastases via hematogenous spread.Jörg R. Siewert: ''Chirurgie.'' 7. Auflage. Springer, 2001, ISBN 3-540-67409-8, p. 150. However, the science is not settled on this point, and there is disagreement about whether metastases can metastasize themselves.D. Hölzel, R. Eckel u. a.
''Distant metastases do not metastasize.''
In: '' Cancer and Metastasis Reviews.'' Band 29, Nummer 4, Dezember 2010, , S. 737–750. doi:10.1007/s10555-010-9260-1. PMID 20878451. (Review). The probability of metastasis in the lymph nodes depends on the density of the lymphatic vessels in the area of the primary tumor. For example, hypopharyngeal or

nasopharyngeal carcinoma Nasopharyngeal carcinoma (NPC), or nasopharynx cancer, is the most common cancer originating in the nasopharynx, most commonly in the postero-lateral nasopharynx or pharyngeal recess ( fossa of Rosenmüller), accounting for 50% of cases. NPC occurs ...

s metastasize extremely quickly to the nearby tissue areas, which are rich in lymphatic vessels.

Classification

Lymph node metastases are usually classified according to the

TNM staging system The TNM Classification of Malignant Tumors (TNM) is a globally recognised standard for classifying the extent of spread of cancer. It is a classification system of the anatomical extent of tumor cancers. It has gained wide international acceptance ...

(T = tumor, N = nodes = lymph nodes, M = metastasis). N0 means that there are no signs of lymph node involvement, and the numbers indicate increasing levels of spread to lymph nodes. However, staging systems varies according the type of primary tumor.Michael Reiß: ''Facharztwissen HNO-Heilkunde.'' Springer, 2009, ISBN 978-3-540-89440-7, p. 126–127.

Frequency

The probability of metastasis to lymph nodes depends on the nature of the primary tumor. In the case of sarcomas, for example, lymph nodes are only very rarely affected. In the case of the much more common carcinomas, especially for the particularly aggressive types, the probability is considerably higher. Above all, however, it depends on the local spread of the primary tumor, its infiltration level, and the tumor size. In many carcinomas, the first metastases are found in the lymph nodes. These include, for example, pancreatic cancer,

head and neck cancer Head and neck cancer develops from tissues in the lip and oral cavity (mouth), larynx (throat), salivary glands, nose, sinuses or the skin of the face. The most common types of head and neck cancers occur in the lip, mouth, and larynx. Symptoms ...

and

malignant melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ...

. In the majority of

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a r ...

cases, too, the first metastases are found in the lymph nodes, specifically in the

axillary lymph nodes The axillary lymph nodes or armpit lymph nodes are lymph nodes in the human armpit. Between 20 and 49 in number, they drain lymph vessels from the lateral quadrants of the breast, the superficial lymph vessels from thin walls of the chest and th ...

Symptoms and diagnosis

Lymph node metastases are usually painless. This contrasts with

lymphadenitis Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In cl ...

(inflammation of the lymph nodes, such as due to a viral infection), in which the lymph nodes are both enlarged and painful when pressed on. Enlarged lymph nodes can be identified by

palpation Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...

(pressing on the spots to feel lumps under the skin).

Sonography Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, musc ...

(ultrasound) can be used as a further diagnostic method. In some cases, lymph node metastases are the first symptom of cancer.

Treatment

{{Main, Lymphadenectomy Lymph_node_NPC

The treatment of the lymph node metastases is usually part of the treatment of the primary tumor. If the primary tumor is operable, all lymph nodes located in the lymphatic drainage area of the diseased organ are often removed. This procedure is called a

lymphadenectomy Lymphadenectomy or lymph node dissection is the surgical removal of one or more groups of lymph nodes. It is almost always performed as part of the surgical management of cancer. In a regional lymph node dissection, some of the lymph nodes in the ...

(lymph node removal). With

sentinel lymph nodes The sentinel lymph node is the hypothetical first lymph node or group of nodes draining a cancer. In case of established cancerous dissemination it is postulated that the sentinel lymph nodes are the target organs primarily reached by metastasiz ...

, a different concept is used in some cancers, specifically

and prostate cancer . The sentinel lymph node is the first lymph node in the drainage area of the tumor lymph. If this is not affected, the more distant lymph nodes are very likely tumor-free and do not have to be removed. The need to remove lymph node metastases is a controversial topic.D. Hölzel, J. Engel: (PDF; 462 kB) In: ''Zentralbl Chir.'' 133, 2008, p. 582–589. doi:10.1055/s-0028-1098738

References

Cancer