A sentinel lymph node is the first lymph node that cancer is likely to spread to from a primary tumor. A sentinel lymph node biopsy identifies, removes, and examines this lymph node to determine if cancer cells are present. If cancer is found, it indicates the cancer may have spread to other lymph nodes or organs. Examining the sentinel lymph node helps determine the cancer stage and guides treatment planning. The procedure also reduces potential side effects of full lymph node surgery like lymphedema. Sentinel lymph node biopsies are used for cancers like breast cancer, melanoma, and others.

1. Sentinel lymphnode
Dr.Vikram Prabhakar

2. What is a sentinel lymph node?
• A sentinel lymph node is defined as the first
lymph node to which cancer cells are most
likely to spread from a primary tumor.
• Sometimes, there can be more than one
sentinel lymph node.

3. What is a sentinel lymph node biopsy?
• It is a procedure in which the sentinel lymph
node is identified, removed, and examined to
determine whether cancer cells are present.
• A positive SLNB result indicates that cancer
may be present in other nearby regional
lymph nodes and, possibly, other organs.

4. • This information can help a doctor determine
the stage of the cancer (extent of the disease
within the body) and develop an appropriate
treatment plan.
• Also, reduces the potential adverse effects of
lymph node surgery like Lymphedema,
numbness, tingling, or pain at the site of the
surgery

5. Uses
• Breast
• Melanoma
• Others: colorectal cancer, gastric cancer,
esophageal cancer, head and neck cancer,
thyroid cancer, and non-small cell lung cancer

7. Breast
• SNB for smaller tumors (T1 and T2)
• multicentric tumors
• DCIS, when mastectomy or immediate
reconstruction is planned
• for older or obese patients
• in male breast cancer

8. Intra operative assessment
a) A positive imprint/smear is of immediate
practical assistance, but negative findings are
not definitive evidence that a node is tumor
free.
b) The quality of frozen tissue preparations is
seldom as good as those prepared from well-
fixed tissue, and incomplete sections may
exclude the critical subcapsular sinus. Prior
freezing may compromise the quality of paraffin
section histology.

9. Sampling of SLN
• Limited step sections from the block (top level
plus one or two sections cut at 200- to 500-
μm intervals into the block) enhance
detection of micrometastases by allowing
evaluation of more of the subcapsular sinus,
the location in which micrometastases are
most often found.
• Superficial serial sections limit sampling to
the upper levels of the block.

10. • Help to detect, macrometastases (> 2.0 mm)
and most micrometastases (> 0.2 mm to 2.0
mm pN1mi) will be detected on limited H&E-
stained step sections.
• In some patients, isolated tumor cells and
clusters (≤ 0.2 mm or <200 confluent
cellpN0i+) will also be detected with use of
this sectioning technique, particularly if
immunohistochemical analysis (IHC) is utilized.

15. Kindly leave a message if
you liked it and follow for
more topics