[481] Sentinel Lymph Node Biopsies in Melanoma: A Retrospective Review of Outcomes and Tumor Burden.

Philip Fong, William R Porter, Mitual B Amin, Richard Keiden, Rajwant K Malhotra. William Beaumont Hospital, Royal Oak, MI

Background: Since the early 1990s, it has been seen that sentinel lymph node (SLN) biopsy for melanoma is a good predictor for involvement of the associated lymph node basin. As such, SLN dissection has been recommended for patients with clinically uninvolved nodal basins, with a primary lesion thickness greater than 1 mm. The purpose of this study was to correlate tumor burden in SLNs with clinical outcome.
Design: 99 patients from 1999 to 2008 with biopsy proven melanoma who also underwent sentinel lymph node biopsies were selected for this study. Melanoma sentinel lymph node protocol was performed which included immunohistochemical staining for S-100 protein, MART-1 and HMB-45. All skin biopsies were evaluated for traditional melanoma parameters.
Results: 65 patients had Breslow's tumor thickness of 1-4mm, and 8 had a tumor thickness of greater than 4mm. Also included in this study were 26 patients, with a tumor thickness under 1mm.
23 patients had positive sentinel lymph nodes (24%). The number of lymph nodes submitted ranged from 1-9. Isolated tumor cell (ITC) metastasis were identified in 6 patients, micrometastasis (MiM) in 9 patients, and metastasis (>2mm) were identified in 8 patients. Of the 6 ITCs, one had local recurrence and one had systemic failure. Of the 9 MiM, one had regional and systemic recurrence. Of the 8 patients with metastasis, six had systemic recurrence.
Of the 65 patients with a tumor thickness of 1-4mm, 17 had positive SLN (ITC: 5; MiM: 5; M: 7). Of the 8 patients with a tumor thickness greater than 4mm, 3 had positive SLN (ITC: 0; MiM: 2; M: 1). Of the 26 patients with a tumor thickness under 1 mm, 3 had positive SLN (ITC: 1; MiM: 1; M: 1). Seven patients had more then one lymph node positive, but did not correlate with Breslow's tumor thickness or tumor burden.
Conclusions: Sentinel lymph node biopsy is an effective method at predicting outcome in patients with melanoma. Breslow's tumor thickness did not correlate with metastatic tumor burden. Metastasis (>2mm) did correlate with increased local and systemic failure.
Category: Dermatopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 110, Tuesday Morning

 

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