Lymph node grossing

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

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

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.