In current practice there is wide variation in how lymph nodes from regional lymphadenectomies are dissected and processed and the methods described below should only be considered as a guide.
Specimens should be examined carefully to maximise lymph node yield. Each lymph node must be blocked, examined and recorded in such a way so as to enable accurate measurement of lymph node numbers and involvement at microscopic examination. This is usually achieved by manual dissection of fixed tissue with careful examination by inspection and palpation.
Small lymph nodes, <5mm in maximum dimension, usually will not require dissection and can be submitted whole.
Lymph nodes > 5mm, serially section at 2mm intervals looking for grossly identifiable deposits.7
Please note that some institutions serially section all lymph nodes at 2mm whether for sentinel node analysis or for routine regional lymph node evaluation with the entire lymph node submitted for histological evaluation.8
Macroscopically involved lymph nodes may be bisected along the median plane to demonstrate the relationship of tumour to the capsule. One section of a macroscopically involved node is sufficient.
Where extracapsular extension is apparent or suspected, lines of dissection should extend through adjacent tissues to allow microscopic evaluation of extracapsular invasion.
The lymph node or tumour closest to the surgical margin should be so identified and sampled.9,10 If extranodal tumour is close to the surgical soft tissue margin, the margin may be painted with ink. If oriented specify the margin.
If skin is present, identify and sample the previous biopsy track if possible. Any abnormal area should be sampled according to the skin protocol. In the absence of any abnormality one representative block is adequate.
If skin is present, identify and sample the previous biopsy track if possible. Any abnormal area should be sampled according to the skin protocol. In the absence of any abnormality one representative block is adequate.
Every lymph node identified should be examined histologically. The presence of matted lymph nodes or extension of tumour to specimen edges is rare but should be reported if apparent to assist with radiation therapy planning.9,10
The description of non-sentinel lymph nodes should include the location of nodes (as described by the clinician) according to the standard code.3
The axillary contents can be divided into three anatomical levels if the surgeon has marked the specimen appropriately.3,4 The apical lymph node should be separately identified, if so designated by the surgeon.
Axilla
- Level
- Internal mammary chain, specify interspace if provided.
Groin
- Other, specify
- Iliac
- Femoral
- Inguinal