Sentinel Lymph Node Biopsy and Axillary Dissection

CHAPTER 23 Sentinel Lymph Node Biopsy and Axillary Dissection







BACKGROUND


Lymph node staging is an important component of the surgical management of both malignant melanoma and breast cancer. Until the 1990s, complete regional lymphadenectomy represented the standard approach to achieving this goal. The development of sentinel lymph node biopsy has allowed for the more limited, selective treatment of regional lymph nodes and has decreased the number of complete regional dissections performed in patients without nodal metastases. This procedure, as it is currently performed, maps the lymphatic drainage from the skin or breast to a primary lymph node or nodes, using a vital blue dye or a radioisotope-labeled tracer. Surgical excision and pathologic evaluation of these nodes for metastases allows for reliable staging and the prediction of additional lymph node metastases. Generally, patients found to have metastases in the sentinel node or nodes (i.e., positive sentinel node biopsy) undergo completion lymphadenectomy. In contrast, patients with negative findings on sentinel lymph node biopsy can safely forgo lymphadenectomy in view of the very low risk of nonsentinel nodal involvement. Sentinel lymph node biopsy also allows a meticulous histologic evaluation of multiple sections augmented by immunohistochemical staining for melanoma-related antigens and cytokeratins for breast cancer. This, not infrequently, allows more precise staging of both diseases.


With few exceptions, the axillary lymph nodes represent the first site of metastasis from melanomas of the upper extremities and upper trunk and cancers of the breast. This chapter focuses on axillary lymph node biopsy; however, the techniques described are applicable to sentinel lymph node biopsy performed at other sites (e.g., the groin for lower extremity melanomas and the cervical, parotid, and occipital lymph nodes for head and neck melanomas). Axillary dissection, which remains an important component of the management of breast cancer and melanoma and typically follows a positive finding on sentinel lymph node biopsy, is also described.



INDICATIONS FOR SURGERY






PREOPERATIVE EVALUATION


The components of the preoperative evaluation of patients with breast cancer and melanoma are distinct and are discussed separately.




May 26, 2018 | Posted by in GENERAL SURGERY | Comments Off on Sentinel Lymph Node Biopsy and Axillary Dissection

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