Lymph node metastasis

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

The tumor cells reach the lymph nodes via this lymphatic pathway, where they remain and proliferate.

[2][3] 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.

[5] The probability of metastasis to lymph nodes depends on the nature of the primary tumor.

Enlarged lymph nodes can be identified by palpation (pressing on the spots to feel lumps under the skin).

If the primary tumor is operable, all lymph nodes located in the lymphatic drainage area of the diseased organ are often removed.

Histopathology of a lymph node with metastatic invasive ductal carcinoma from the breast, H&E stain, with the presence of extranodal (or "extracapsular") extension (arrows), as tumor outside the fibrous capsule of the lymph node.
Lymphadenectomy of a lymph node in the neck