Lymph node metastasis is the spread ( metastasis) of

cancer cells Cancer cells are cells that divide continually, forming solid tumors or flooding the blood with abnormal cells. Cell division is a normal process used by the body for growth and repair. A parent cell divides to form two daughter cells, and these d ...

into a

lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inclu ...

. 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 enlar ...

. 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. This is because the lymphatic fluid (lymph) of the cancerous

organ Organ may refer to: Biology * Organ (biology), a part of an organism Musical instruments * Organ (music), a family of keyboard musical instruments characterized by sustained tone ** Electronic organ, an electronic keyboard instrument ** Hammond ...

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, 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 ''Cancer and Metastasis Reviews'' is a quarterly peer-reviewed medical review journal covering oncology and the development of new cancer treatments. It was established in 1982 and is published by Springer Science+Business Media. The edito ...

.'' 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 carcinomas 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 (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

carcinoma Carcinoma is a malignancy that develops from epithelial cells. Specifically, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that arises from cells originating in the endodermal, mesodermal ...

s, 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 Pancreatic cancer arises when cell (biology), cells in the pancreas, a glandular organ behind the stomach, begin to multiply out of control and form a Neoplasm, mass. These cancerous cells have the malignant, ability to invade other parts of t ...

, head and neck cancer and malignant melanoma. In the majority of breast cancer cases, too, the first metastases are found in the lymph nodes, specifically in the axillary lymph nodes.

Symptoms and diagnosis

Lymph node metastases are usually painless. This contrasts with lymphadenitis (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 (pressing on the spots to feel lumps under the skin). Sonography (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 (lymph node removal). With sentinel lymph nodes, a different concept is used in some cancers, specifically breast cancer and

prostate cancer Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...

. 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