Skin melanocytic tumor


Sentinel node biopsy

Topic Completed: 1 May 2013

Minor changes: 3 November 2020

Copyright: 2002-2021,, Inc.

PubMed Search: Sentinel node biopsy melanoma

Christopher S. Hale, M.D.
Page views in 2020: 1,230
Page views in 2021 to date: 1,361
Cite this page: Hale CS. Sentinel node biopsy. website. Accessed November 27th, 2021.
Definition / general
  • Sentinel lymph node is defined as first extracutaneous target of lymphogenous tumor cell spread and potential source of subsequent lymph node metastases and distant metastases (eMedicine)
  • Interval sentinel nodes: nodes receiving direct lymphatic drainage from primary site but lying between tumor and a recognized node field (Ann Surg Oncol 2011;18:3292)
  • Lymphatic mapping and sentinel lymph node biopsy are widely used for staging
Diagrams / tables

Images hosted on other servers:

Intraoperative lymphatic mapping and sentinel node

Prognostic factors

Selected protocols for sentinel nodes:
Clinical images

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Lymphatic mapping

Intraoperative left
axillary node
seen after uptake
with blue dye

Microscopic (histologic) images

Images hosted on other servers:

D2-40+ lymphatic in tumor

Increased 11q13 (cyclin D1) by FISH

Tattoo pigment (not tumor)

Positive stains
Molecular / cytogenetics description
  • RT-PCR: prognostic significance of melanocytic mRNA in histologically negative nodes is controversial (significant - APMIS 2008;116:199, not significant - Mod Pathol 2007;20:427)
  • RT-PCR detects significant sentinel node metastases that are missed by histopathology but overestimates number of patients with clinically significant metastases (Melanoma Res 2003;13:313)
  • FISH detects chromosomal aberrations in 83% of nodal metastatic melanoma vs. 6% of nodal nevi (Am J Surg Pathol 2010;34:231)

Wide excision and sentinel node mapping

Differential diagnosis
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