August 6, 2023

In pathology, extranodal extension (ENE) refers to the spread of tumour cells beyond the lymph node capsule into the surrounding tissues. This process is observed in various types of cancers that have metastasized to lymph nodes. ENE is considered a marker of aggressive disease and can significantly impact the staging, prognosis, and treatment strategy for cancer patients.

Why is extranodal extension important?

• Staging: The presence of ENE often leads to a higher staging of cancer, indicating a more advanced disease. This is because ENE suggests that the cancer is more aggressive and has the potential to spread more readily through tissues outside the lymphatic system.
• Prognosis: Patients with cancers exhibiting ENE generally have a poorer prognosis compared to those without ENE. It is associated with an increased risk of cancer recurrence and reduced survival rates.
• Treatment planning: The detection of ENE can influence the treatment approach, often leading to more aggressive treatment strategies. This may include additional surgical intervention to remove more extensive areas of affected tissue, as well as more intensive chemotherapy or radiotherapy to target any residual disease.

How is extranodal extension detected?

Pathologists identify ENE during the microscopic examination of lymph nodes removed during surgery. The assessment involves looking for evidence of tumor cells breaking through the lymph node capsule and spreading into adjacent tissues.

The identification of ENE is important in the management of cancers, particularly head and neck cancers, breast cancer, and melanoma, among others. Its detection highlights the importance of comprehensive pathological evaluation of lymph nodes in the context of cancer surgery and the need for potentially more aggressive treatment to address the increased risk of metastasis and recurrence.

About this article

Doctors wrote this article to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

Other helpful resources

Atlas of pathology