The number of lymph nodes identified in a colectomy specimen performed to resect a colon cancer is important for accurately staging the patient. The number of lymph nodes retrieved is affected by a number of factors.
|
Parameter |
Comment |
|
length of colon |
The longer the segment, the more lymph nodes can be expected. |
|
location of colon |
Lymph nodes are more readily found in some parts of the colon than others. |
|
amount of mesentery |
Removing the colon with little mesentery attached may result in few lymph nodes. |
|
tumor close to one of the margins |
Some of the lymph nodes draining the tumor may not have been removed. |
|
size and depth of tumor invasion |
Tumor metastases are more likely with a large, deeply invasive tumor. |
|
degree of inflammation and reactive change secondary to ulceration or colitis |
Chronic inflammation may be associated with lymphoid hyperplasia. |
|
tumor's tendency to lymphatic invasion |
Some tumors cause significant nodal metastases while others do not. |
|
experience and care of the pathologist |
A careful dissection will reveal more lymph nodes than a sloppy one. |
|
use of fixative for demonstrating lymph nodes |
These turn lymph nodes white, making them easy to find in mesenteric fat. |
|
lymphopenia prior to therapy |
Lymphopenia can result in small lymph nodes that may be hard to find. |
|
lymphopenia secondary to preoperative chemoradiation |
Chemoradiation can cause the tumor and lymph nodes to shrink. |
where:
• Many lymph nodes identified with lymph node revealing solutions are quite small, often only 1 or 2 mm in diameter.
As many lymph nodes as possible should be identified. If less than 12 lymph nodes are found after the initial dissection, then the specimen should be re-examined, preferably using a fixative for demonstrating lymph nodes. If there are no more lymph nodes, then there are no more lymph nodes.
Specialty: Hematology Oncology, Surgery, general, Gastroenterology
ICD-10: ,
