04 Malignant Skin Lesions

Sentinel lymph node sln status is the single most

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Unformatted text preview: ph node biopsy (SLNB) [see 3:6 Lymphatic Mapping and Sentinel Lymph Node Biopsy], which has essentially replaced elective lymph node dissection. Sentinel lymph node (SLN) status is the single most important predictor of survival in patients with melanoma40 and is now considered a standard approach in the United States. A positive result is defined as the presence of identifiable melanoma cells on routine hematoxylin-eosin staining, immunohistochemical staining with S100 or HMB-45, or both. Preoperative lymphatic mapping via lymphoscintigraphy is often quite helpful, in that many lesions have variable drainage basins that cannot be predicted clinically, and some lesions even drain to contralateral nodes.41 The greatest accuracy is achieved with SLNB when both radioactive colloid and blue dye are used.42 SLNB should not be performed in patients with clinically positive nodes or in those who would otherwise not be considered for lymphadenectomy. It is generally recommended for patients who are at moderate or high risk for harboring occult regional node metastases. In patients with T1 primary tumors, SLNB may be considered in selected scenarios (i.e., primary tumor ulceration or extensive regression, a high mitotic rate, a Clark level IV lesion, or a positive deep margin).38 The impact of SLNB on the management of melanoma has been impressive.The results greatly facilitate accurate staging and play an important role in helping the clinician decide whether to perform completion lymph node dissection (CLND) or to offer adjuvant therapy. Several studies have demonstrated significant differences in survival and disease-free interval between SLN-negative patients and SLN-positive patients.43,44 One such study reported a 3-year disease-free survival rate of 88.5% in SLN-negative patients, compared with 55.8% in SLN-positive patients.43 Surgical treatment of stage III melanoma Completion lymph node dissection. At present, CLND is recommended for management of the regional lymph node drainage basin in the presence of a positive SLN. Some clinical trial results do not appear to support this recommendation. For example, four randomized trials failed to demonstrate any overall survival benefit for patients randomly assigned to undergo elective lymph node dissection.45-48 It should be noted, however, that most of the patients in these studies did not have lymph node metastases, and thus, the trials did not have sufficient statistical power to detect a small survival benefit.49 Other trial results, however, do support the recommendation for CLND in node-positive patients, including those of the World Health Organization Program Trial No. 14, which demonstrated that the 5-year survival rate in patients with occult nodal metastases detected at elective lymph node dissection was significantly better than that in patients who underwent delayed lymphadenectomy at the time when palpable nodal metastases developed (48% versus 27%).47 Nonetheless, the impact of CLND on overall survival is still a matter for debate. The results of the first Mul...
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This note was uploaded on 03/21/2011 for the course ONC 01 taught by Professor Dzodic during the Spring '11 term at Multimedia University, Cyberjaya.

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