Lymph node grossing

Picture showing a lymph node at gross (arrow). (Mikael Häggström/WC)

Lymph node grossing is an important element of the lymph node assessment in cancer staging.

General

In many cancer types, the lymph node count is important to quantify, as it is used as a quality metric.

Cases with too few lymph nodes may be under-staged and thus under-treated.

There is no universal lymph node count target; the ideal number of lymph nodes is dependent on the type of cancer.

Gross

Identification of lymph nodes

• Visual.
• Palpation - more important than visual.

Gross interpretation

Normal lymph node:

• Firm (relative to adipose tissue).
• Glistening surface when cut.

Pathologic lymph node:

• White lesions, especially irregular = suggestive of carcinoma.
• White, glistening with lobulated surface - "fish flesh" = suggestive of lymphoma.
  • Subtle lobulation (~1 mm) on section suggestive of follicular lymphoma.

Submission

• The number of lymph nodes in each block should be noted in the gross report. †
• If multiple lymph nodes are present in the one block they should not be sectioned unless inked. ‡
  • For multiple lymph nodes in one block either 1 or 2:
    1. Submit the lymph nodes without sectioning.
    2. Ink the individual lymph nodes different colours before sectioning - so the sections can be matched under the microscope.

Notes:
† It is useful to use the word "possible" when describing lymph nodes; in the gross report "possible lymph node" is preferred over "lymph node". Lymph nodes are not reliably identified at gross.
‡ If multiple lymph nodes are sectioned and these are not marked: it is not possible to reliably count the number of positive lymph nodes. Example: two lymph nodes are bisected and two sections have a small amount of cancer. Is that two positive lymph nodes or one positive lymph node that was bisected? Answer: It is not possible to tell.

See also

• Lymph nodes.
• Lymph node metastasis.