Results of Sentinel Lymph Node Biopsy in Patients With Thin Melanoma

Background Sentinel lymph node (SLN) biopsy has been shown to be a highly accurate method of staging nodal basins in melanoma patients. Although this technique is widely accepted in patients with intermediate-thickness tumors, it is unclear what the indications are for thin (≤1 mm) melanoma. Methods From May 1991 to October 2004, 223 patients with thin melanoma underwent SLN biopsy at Memorial Sloan-Kettering Cancer Center. Most patients with thin melanoma were selected for the procedure because of high-risk clinicopathologic features. Results Nodal metastases were found in eight patients (3.6%) who underwent SLN biopsy. All positive SLNs were found in patients with ≥.75 mm-thick and Clark level IV melanoma (8 of 114; 7%). Age, sex, tumor location, thickness, Clark level, ulceration, regression, tumor-infiltrating lymphocytes, mitotic rate, and number of mapped nodal basins were not predictive of positive SLNs (χ²; P = not significant). With a median follow-up of 25 months, there have been no recurrences or deaths in patients with melanoma <.75 mm. Six patients have had regional and/or systemic recurrences (2.7%), only one of whom had a positive SLN. Three patients have died of melanoma; all had negative SLNs. Conclusions Nodal metastasis in thin melanoma is uncommon, especially in patients with <.75 mm and Clark level II or III melanoma. In our experience, no single clinicopathologic factor was predictive of nodal metastases. The prognostic implications of positive SLNs in thin melanoma remain undefined.     

High isotope counts and sentinel node positivity in patients with melanoma

BACKGROUND: Radioisotope mapping is an essential technical component of sentinel lymph node (SLN) biopsy, and most authors define success by an arbitrary threshold SLN-background ratio. HYPOTHESIS: Few studies have examined the degree to which the relative level of SLN counts correlates with the presence of metastasis. Having removed the SLN with the highest counts, there are no data suggesting how far the surgeon should persist in removing additional SLNs that contain much lower levels of isotope. METHODS: We performed 134 SLN biopsy procedures in 132 patients with melanoma. Successful isotope localization was defined using an SLN/"hottest" SLN ratio; we defined an SLN as any node containing counts at least 10% of that of the hottest SLN. RESULTS: Of 83 patients with more than 1 SLN site identified, 21 (25%) had SLNs that contained metastasis. In 17 (81%) of these cases, the SLN with the highest countcontained tumor, but in 4 (19%) it was benign. Among these 4 patients, the counts of the hottest benign SLNs exceeded those of SLNs positive for metastasis on histological examination by a ratio of at least 10:1, and the counts of the positive SLNs were less than 4:1 of those of the background counts or the presence of blue dye failed to identify the positive SLN. No optimum ratio of SLN/SLN or SLN/background counts identified the positive SLN in all cases. CONCLUSIONS: Although the SLN with the highest counts contained metastasis in 81% of patients with malignant melanoma and multiple SLNs, neither a relatively high isotope count nor the presence of blue dye consistently predicted SLN positivity. For maximum accuracy, SLN biopsy requires the removal of all nodes containing isotope regardless of the relative magnitude of counts and the concurrent use of blue dye to salvage those procedures in which isotope mapping fails.     

Is the “10% Rule” Equally Valid for All Subsets of Sentinel-Node-Positive Breast Cancer Patients?

Background  In breast cancer, a combination of radioisotope and blue dye mapping maximizes the success and accuracy of sentinel node (SLN) biopsy. When multiple radioactive nodes are present, there is no single definition of isotope success, but the popular “10% rule” dictates removal of all SLN with counts >10% of the most radioactive node. Here we determine how frequently a positive SLN would be missed by the 10% rule. Methods  Between 9/96 and 12/04, we performed 6,369 successful SLN biopsies using ^99mTc sulfur colloid and isosulfan blue dye, removing as SLN all radioactive and/or blue nodes, and taking counts from each node ex vivo. Standard processing of all SLNs with a benign frozen section included hematoxylin and eosin (H&E) staining, serial sectioning, and immunohistochemistry (IHC). Results  33% of patients (2,130/6,369) had positive SLNs. Of these patients, 1,387/2,130 (65%) had >1 SLN identified. The most radioactive SLN was benign in 29% (398/1,387), and 107/1,387 (8%) had a positive SLN that was neither blue nor the hottest. From this group 1.7% (24/1387) of patients had positive SLN with counts <10% radioactive counts of the hottest node. The 10% rule captured 98.3% of positive nodes in patients with multiple SLNs. No patient characteristics were predictive of failure of the 10% rule. Conclusion  With combined isotope and blue dye mapping, the 10% rule is a robust guideline and fails to identify only 1.7% (24/1387) of all SLN-positive patients with multiple SLNs. This guideline appears to be equally valid for all subsets of patients.     

Sentinel lymph node biopsies in melanoma: how many nodes do we really need?

BACKGROUND: Sentinel lymph nodes (SLN) biopsy is a widely used method to detect lymphatic spread in patients with cutaneous melanoma. Several methods are used to detect SLNs. Recent reports attempted to identify the adequate number of SLNs to reliably detect malignant spread in regional lymph nodes. METHODS: The radiotracer counts and the pathologic reports of all patients undergoing SLN biopsies were collected prospectively, to determine which of the nodes harboring radiotracer needed to be removed for examination by histopathology between 1998 and 2005. All patients with positive SLN biopsies were investigated in the study. Lymph nodes were ranked according their radiotracer counts and numbered as hottest nodes, second hottest nodes, third hottest nodes, etc. The relationship between radioactivity and the risk of harboring malignancy was determined. RESULTS: Nodal metastases were detected in 55 basins from 53 patients (10.5%). There was a correlation between the radiotracer uptake and risk of harboring malignancy. Excising the 3 hottest nodes and all blue nodes detected 100% of patients with lymphatic malignancy in our series. Most (98%) of positive lymph nodes had radiotracer counts greater than 30% of the hottest node. Only 1 patient (2%) had radioactive count less than 30%, but had visible blue dye. CONCLUSIONS: Removing only the hottest node is inadequate to detect lymphatic spread. On the other hand, removing the 3 hottest nodes and all visible blue nodes is sufficient to detect regional lymphatic spread in patients with cutaneous melanoma. Removing nodes with a radiotracer uptake less than 30% of the hottest nodes may be unnecessary.     

Intraoperative Evaluation of Sentinel Lymph Nodes for Metastatic Melanoma by Imprint Cytology

Background Sentinel lymph node biopsy (SLN) has revolutionized nodal staging. Accurate intraoperative evaluation of SLN permits a single procedure, with lymphadenectomy being performed during the initial operative procedure when the SLN is positive. There is a paucity of literature on intraoperative imprint cytology (IIC) evaluation of the SLN in melanoma. The purpose of this article is to present an update to our experience with IIC for SLN in melanoma. Methods Melanoma patients had SLNs examined by IIC. SLNs were bisected, and imprints were made from each half. Imprints were stained with hematoxylin and eosin and with Diff-Quik. Paraffin-embedded sections were examined with multiple hematoxylin and eosin–stained sections from the SLNs in conjunction with immunohistochemical staining for S-100, Melan-A, and HMB-45 proteins. Results Metastases were identified in 40 (17%) of 229 patients. Of these, 13 patients were detected by IIC (sensitivity, 33%). The negative predictive value was 88%. No false-positive results were identified (specificity, 100%). The positive predictive value was 100%. The accuracy of IIC was 78%. The sensitivity for detecting macrometastases (>2 mm) was better than that for detecting micrometastases (≤2 mm): 62% vs. 16% (P < .01). Patients with positive SLNs by IIC had lymphadenectomy under the same anesthetic. A total of 533 nonsentinel lymph nodes were identified in 42 patients. Only two patients (8%) had positive nonsentinel lymph nodes after a negative IIC. Conclusions IIC is a viable alternative to frozen sectioning when intraoperative evaluation is desired. IIC is significantly more sensitive for macrometastases. IIC evaluation of SLNs in melanoma makes a single operative procedure possible for a significant proportion of patients with regional nodal metastases. Presented at the Society of Surgical Oncology, San Diego, California, March 24, 2006.     

Results of complete lymph node dissection in 83 melanoma patients with positive sentinel nodes

Background: The technique of sentinel lymph node (SLN) biopsy for melanoma provides accurate staging information because the histology of the SLN reflects the histology of the entire basin, particularly when the SLN is negative. Methods: We combined two mapping techniques, one using vital blue dye and the other using radiolymphoscintigraphy with a hand-held gamma Neoprobe, to identify the SLN in 600 consecutive patients with stage I–II melanoma. The SLNs were examined using conventional histopathology and immunohistochemistry for S-100. Results: Eighty-three (13.9%) patients had micrometastatic disease in the SLNs. Thirty percent of patients with primary melanomas greater than 4.0 mm in thickness had positive SLNs, followed by 48 of 267 (18%) of patients with tumors between 1.5 mm and 4 mm, and 12 of 169 (7%) of those with lesions between 1.0 mm and 1.5 mm. No patient with a tumor less than 0.76 mm in thickness had a positive SLN. Sixty-four of the 83 SLN-positive patients consented to undergo complete lymph node dissection (CLND), and five of 64 (7.8%) of the CLNDs were positive. All patients with positive CLNDs had tumor thicknesses greater than 3.0 mm. Conclusions: The rate of SLN-positive patients increases with increasing thickness of the melanoma. SLN-positive patients with primary lesions less than 1.5 mm in thickness may have disease confined to the SLN, thus rendering higher-level nodes free of disease, and may not require a CLND. Presented at the 50th Annual Cancer Symposium of The Society of Surgical Oncology, Chicago, Illinois, March 20–23, 1997.     

The effect of changing gamma count threshold on sentinel lymph node accuracy

PURPOSE: Sentinel lymph node (SLN) biopsy has been increasingly accepted in many centers as an alternative to axillary lymph node dissection in the nodal staging of breast cancer. The goal of SLN biopsy is to accurately stage the axilla while minimizing postoperative morbidity. Theoretically, the continuing search for SLNs disrupts additional lymphatics and impacts on operative time. The gamma count threshold is a predefined threshold percentage of the ex vivo count of the "hottest" SLN, which when applied to each individually excised lymph node determines whether a given lymph node is the SLN or a non-SLN. The higher the threshold percentage, the less the number of lymph nodes will meet the criteria of being an SLN. This study examines the hypothesis that changing the gamma count threshold from 10% to 50% will not significantly affect accuracy or the false-negative rate. METHODS: We retrospectively reviewed the charts of patients who underwent SLN biopsy with or without completion axillary lymph node dissection from March 1995 to January 2001 at Walter Reed Army Medical Center. Data were collected on gamma counts for each SLN and histopathology of each SLN. For each SLN ex vivo gamma count, percentage of the ex vivo gamma count of the "hottest" SLN was calculated. RESULTS: The SLN identification success rate was 94% (163 out of 174 patients). On average, 2.07 SLNs were removed per patient and 58% of patients had more than 1 SLN removed (94 out of 163 patients). Only 10% had 4 or more SLNs removed (17 out of 163 patients). Sentinel lymph node metastasis was found in 21% of patients (35 of 163 patients). Of these 35 patients with positive SLNs, 8 patients had a negative "hottest" SLN when a less radioactive SLN was positive for metastasis. Changing the gamma count threshold from 10% to 50% lowers the extrapolated accuracy from 98% to 95% and increases the extrapolated false-negative rate from 8% to 21%. CONCLUSIONS: The accuracy and false-negative rate of SLN biopsy varies based on the lower limit gamma threshold. Maintaining our 10% gamma count threshold results in acceptable accuracy and false-negative rates comparable to reported literature.     

Selective Sentinel Lymph Node Dissection for Melanoma: Importance of Harvesting Nodes with Lower Radioactive Counts without the Need for Blue Dye

Background

Determining how many sentinel lymph nodes (SLNs) should be removed for melanoma is important. The purpose of this study is to determine the frequency at which nodes that are less radioactive than the “hottest” node (which is negative) are positive for melanoma, how low of a radioactivity should warrant harvest, and if isosulfan blue is necessary.

Methods

We reviewed 1,152 melanoma patients who underwent lymphoscintigraphy with technetium, with or without blue dye, and SLN dissection from 1996 to 2008. SLNs with radioactivity ≥10% of the “hottest” SLN, all blue nodes, and all suspicious nodes were removed and analyzed. The miss rate was calculated as the proportion of node positive cases in which the “hottest” SLN was negative.

Results

SLNs were identified in 1,520 nodal basins in 1,152 patients. SLN micrometastases were detected in 218 basins (14%) in 204 patients (18%). In 16% of SLN-positive patients (33/204 patients), the positive SLN was found to have a lower radioactive count than the “hottest” SLN, which was negative. In 21 of these cases, the positive SLNs had radioactivity ≤50% of the “hottest” SLN. The 10% rule significantly reduced the miss rate to 2.5% compared with removal of only the “hottest” SLN (miss rate = 16%). Also, blue dye did not significantly decrease the miss rate compared with radiocolloid alone using the 10% rule.

Conclusions

To decrease the miss rate, all SLNs with ≥10% of the ex vivo radioactivity of the “hottest” SLN should be removed and blue dye is not essential.     

Primary Cutaneous Melanoma with Regression Does not Require a Lower Threshold for Sentinel Lymph Node Biopsy

Introduction Histological evidence of primary tumor regression (RG) is observed in 35% or fewer patients with cutaneous melanoma. Some advocate a lower threshold for sentinel lymph node (SLN) biopsy when RG is present. Methods We identified 1,349 patients presenting to our center with clinically localized cutaneous melanoma between 1995 and 2004. Of these, 344 demonstrated histological RG in their primary melanoma. A retrospective analysis of their medical records was performed to obtain clinical and pathological information. Results The median Breslow depth for the 344 patients with RG was 1.1 mm versus 1.5 mm for 1,005 patients with no regression (NRG) (P < 0.005). SLN biopsy was performed in 64% of patients with RG and 72% without. Positive SLN was more common in those with NRG than in those with RG (18% vs 10%, P = 0.005). Only one RG patient with thin melanoma (≤1 mm, Clark IV) had a positive SLN. When stratified by Breslow depth, patients with RG had lower rates of SLN positivity in all groups (≤1.0mm, >1.0 and ≤2.0mm, >2 and ≤4 mm, and >4.0 mm). Recurrence was more common in patients with NRG (21% vs 12%; P < 0.005). Both local and systemic recurrence occurred more commonly in patients with NRG (4% vs 1%, P = 0.002 and 8% vs 3%, P < 0.005, respectively) Conclusions The presence of histological RG in a primary melanoma predicts neither SLN positivity when stratified by Breslow depth nor increased risk of recurrence when compared with melanomas with NRG.     

The Progression of Melanoma Nodal Metastasis Is Dependent on Tumor Thickness of the Primary Lesion

Background: Recent results of several clinical trials using the technique of intraoperative lymphatic mapping and sentinel lymph node (SLN) biopsy confirm the validity of the concept of there being an order to the progression of melanoma nodal metastases. This report reviews the H. Lee Moffitt Cancer Center experience with this procedure, one of the largest series described to date. These data demonstrate that the involvement of the SLNs, as well as higher-echelon nodes, is directly proportional to the melanoma tumor thickness, as measured by the method of Breslow.Methods: The investigators at the H. Lee Moffitt Cancer Center retrospectively reviewed their experience using lymphatic mapping and SLN biopsies in the treatment of malignant melanoma. All eligible patients with primary malignant melanomas underwent preoperative and intraoperative mapping of the lymphatic drainage of their primary sites, along with SLN biopsies. All patients with positive SLNs underwent complete regional basin nodal dissection. For 20 consecutive patients with one positive SLN, all of the nodes from the complete lymphadenectomy were serially sectioned and examined by S-100 immunohistochemical analysis, to detect additional metastatic disease.Results: Six hundred ninety-three patients consented to undergo lymphatic mapping and SLN biopsy. The SLNs were successfully identified and collected for 688 patients, yielding a 99% success rate. One hundred patients (14.52%) showed evidence of nodal metastasis. The rates of SLN involvement for primary tumors with thicknesses of <0.76 mm, 0.76–1.0 mm, 1.0–1.5 mm, 1.5–4.0 mm, and >4.0 mm were 0%, 5.3%, 8%, 19%, and 29%, respectively. Eighty-one patients underwent complete lymph node dissection after observation of a positive SLN, and only six patients with positive SLNs demonstrated metastatic disease beyond the SLN (7.4%). The tumor thicknesses for these six patients ranged from 2.8 to 6.0 mm. No patient with a tumor thickness of <2.8 mm was found to have evidence of metastatic disease beyond the SLN in complete lymph node dissection. All 20 patients with a positive SLN for whom all of the regional nodes were serially sectioned and examined by S-100 immunohistochemical analysis failed to show additional positive nodes.Conclusions: These results suggest that regional lymph node involvement may be dependent on the thickness of the primary tumor. As the primary tumor thickness increases, so does the likelihood of involvement of SLNs and higher regional nodes in the basin beyond the positive SLNs.Presented at the 51st Annual Meeting of The Society of Surgical Oncology, San Diego, California, March 26–29, 1998.     

American Joint Committee on Cancer Clinical Stage as a Selection Criterion for Sentinel Lymph Node Biopsy in Thin Melanoma

Background A significant proportion of newly diagnosed melanomas are thin lesions (≤1.00 mm). Because tumor thickness correlates with the risk for nodal metastases, sentinel lymph node (SLN) biopsy in this subset is controversial. Incorporating other prognostic factors (Clark level and ulceration), we evaluated the 6th edition American Joint Committee on Cancer (AJCC) clinical stage as a simple and widely applicable guideline for offering SLN biopsy for thin melanoma. Methods This study was a review of a prospective melanoma SLN database from 1993 to 2003 with emphasis on SLN positivity rates based on the 6th edition AJCC primary tumor thickness intervals and clinical stage. Results Three hundred five patients underwent SLN biopsy, with an overall positivity rate of 17.7%. By the 6th edition AJCC, lesions ≤1.00 mm had an SLN positivity rate of 6.6%. By 6th edition clinical stage, SLN positivity rates were 4.9% for stage IA and 10.4% for stage IB. By using stage IA as the criterion for not offering SLN biopsy, this procedure would have been avoided in 46% (39 of 85) of ≤1.00-mm melanoma patients with a negative SLN. Conclusions Sixth edition AJCC clinical stage IB as a selection criterion for performing SLN biopsy in thin melanoma identifies most patients with a positive SLN while also avoiding a negative SLN biopsy in many patients. Until additional widely accepted and validated selection criteria are available, SLN biopsy for clinical stage IB, but not stage IA, thin melanomas is a reasonable approach.     

The Amount of Metastatic Melanoma in a Sentinel Lymph Node: Does It Have Prognostic Significance?

Background: The amount of metastatic disease in the sentinel lymph node (SLN) is examined as a prognostic factor in malignant melanoma.Methods: SLN mapping was performed on 592 patients with stage I and II malignant melanoma from March 1, 1994, through December 31, 1999. One hundred four patients were found to have 134 sentinel SLNs containing metastatic melanoma. The slides were reviewed, and the size of the metastatic melanoma in each SLN was measured. The size of the metastatic deposit was defined as macrometastasis (>2 mm), micrometastasis (2 mm), a cluster of cells (10–30 grouped cells) in the subcapsular space or interfollicular zone, or isolated melanoma cells (1 to 20 individual cells) in subcapsular sinuses.Results: The number of metastases in each SLN was isolated melanoma cells, n = 5 (3.7%); cluster of cells, n = 35 (26.1%); 2 mm, n = 45 (33.6%); and >2 mm, n = 49 (36.7%). Seventy-nine patients (76%) had a single positive SLN. The size of the largest nodal metastasis was used to stratify patients with multiple positive SLNs. The overall 3-year survival for patients with SLN micrometastases was 90%, versus 58% for patients with SLN macrometastases (P = .004).Conclusions: The amount of metastatic melanoma in an SLN is an independent predictor of survival. Patients with SLN metastatic deposits >2 mm in diameter have significantly decreased survival.     

Sentinel node staging of primary melanoma by the "10% rule": pathology and clinical outcomes

BACKGROUND: Surgical staging of clinically node-negative primary melanoma involves identification and removal of "sentinel" lymph nodes (SLNs). Although some suggest removal of only the "hottest" SLN, the "10% rule" dictates that nodes are removed until the background count is 10% or less of the count of the "hottest" node. METHODS: To determine the utility of the 10% rule, a university database of clinically node-negative melanomas surgically staged by using this rule was examined. RESULTS: Twenty-two of 177 cases (12.5%; 15% of T2 and T3 lesions) were SLN positive. Among the SLN-positive cases, use of the rule resulted in removal of 21 additional nodes, 7 of which contained tumor. In 3 cases (14%), the positive SLN was not the "hottest" node. At 49 months of mean follow-up time, overall survival was 63% for SLN-positive patients versus 92% for SLN-negative patients (P = .01). CONCLUSIONS: Sentinel node staging of melanoma by the 10% rule provides significant prognostic information and a modest increase in tumor detection compared with removal of only the "hottest" node.     

Micrometastasis to In-Transit Lymph Nodes From Extremity and Truncal Malignant Melanoma

Background: The sentinel lymph node (SLN) is the first lymph node in the regional nodal basin to receive metastatic cells. In-transit nodes are found between the primary melanoma site and regional nodal basins. To date, this is one of the first reports on micrometastasis to in-transit nodes.Methods: Retrospective database and medical records were reviewed from October 21, 1993, to November 19, 1999. At the UCSF Melanoma Center, patients with tumor thickness >1 mm or <1 mm with high-risk features are managed with preoperative lymphoscintigraphy, selective SLN dissection, and wide local excision.Results: Thirty (5%) out of 557 extremity and truncal melanoma patients had in-transit SLNs. Three patients had positive in-transit SLNs and negative SLNs in the regional nodal basin. Two patients had positive in-transit and regional SLNs. Three patients had negative in-transit SLNs but positive regional SLNs. The remaining 22 patients were negative for in-transit and regional SLNs.Conclusions: In-transit SLNs may harbor micrometastasis. About 10% of the time, micrometastasis may involve the in-transit and not the regional SLN. Therefore, both in-transit and regional SLNs should be harvested.Supported in part by a grant from the Eva B. Buck Charitable Trust.     

Practical guidelines for optimal gamma probe detection of sentinel lymph nodes in breast cancer: results of a multi-institutional study. For the University of Louisville Breast Cancer Study Group

INTRODUCTION: Multiple radioactive lymph nodes are often removed during the course of sentinel lymph node (SLN) biopsy for breast cancer when both blue dye and radioactive colloid injection are used. Some of the less radioactive lymph nodes are second echelon nodes, not true SLNs. The purpose of this analysis was to determine whether harvesting these less radioactive nodes, in addition to the "hottest" SLNs, reduces the false-negative rate. METHODS: Patients were enrolled in this multicenter (121 surgeons) prospective, institutional review board-approved study after informed consent was obtained. Patients with clinical stage T1-2, N0, M0 invasive breast cancer were eligible. This analysis includes all patients who underwent axillary SLN biopsy with the use of an injection of both isosulfan blue dye and radioactive colloid. The protocol specified that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest node should be removed and designated SLNs. All patients underwent completion level I/II axillary dissection. RESULTS: SLNs were identified in 672 of 758 patients (89%). Of the patients with SLNs identified, 403 patients (60%) had more than 1 SLN removed (mean, 1.96 SLN/patient) and 207 patients (31%) had nodal metastases. The use of filtered or unfiltered technetium sulfur colloid had no impact on the number of SLNs identified. Overall, 33% of histologically positive SLNs had no evidence of blue dye staining. Of those patients with multiple SLNs removed, histologically positive SLNs were found in 130 patients. In 15 of these 130 patients (11.5%), the hottest SLN was negative when a less radioactive node was positive for tumor. If only the hottest node had been removed, the false-negative rate would have been 13.0% versus 5.8% when all nodes with 10% or more of the ex vivo count of the hottest node were removed (P =.01). CONCLUSIONS: These data support the policy that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest SLN should be harvested for optimal nodal staging.     

How many lymph nodes are enough during sentinel lymphadenectomy for primary melanoma?

BACKGROUND: Sentinel lymph node (SLN) biopsy has been shown to reliably identify nodal metastases and the subsequent need for further surgical and adjuvant therapy in patients with cutaneous melanoma. Although SLN identification rates have improved with the addition of radioactive colloid to the blue dye technique, it remains unclear how many lymph nodes should be removed to accurately determine the histologic status of the nodal basin. The objective of this study was to determine the optimal extent of SLN biopsy in these patients. METHODS: The records of 633 consecutive patients with melanoma (765 nodal basins) whose primary treatment included SLN biopsy with the use of a combination of blue dye and technetium Tc 99 labeled sulfur colloid were reviewed. SLN biopsy consisted of the removal of all of the blue-stained nodes and all nodes with radiotracer uptake activity of at least twice background. RESULTS: SLN biopsy was successful in 765 of 772 basins (99%). A mean of 1.9 SLNs (median, 2 SLNs) per basin were excised. At least 3 SLNs were removed in 176 basins (23%). The overall histologic status of a basin was always established by the first or second SLN harvested (ie, in no patient was the third or subsequent SLN positive when 1 of the first 2 was not). Of the 124 basins containing lymphatic metastases, the SLN that contained the maximal radiotracer uptake (hottest) and/or stained blue was pathologically positive in 118 basins (95%). In only 6 of the 124 positive basins (5%) was the sole evidence of occult nodal metastases identified in an SLN that was neither blue-stained nor the hottest. All but 1 of these SLNs had counts that were at least 66% of the hottest node in the basin. CONCLUSIONS: With a combined modality approach to SLN biopsy, removal of more than 2 SLNs did not provide information that upstaged any patient with primary melanoma. Removal of additional nonblue SLN(s) that contained radioactive counts of at least twice background but lower than two thirds of the SLNs with maximal radiotracer uptake affected patient management in less than 0.2% of all cases. These findings may be helpful in minimizing the extent of surgery and perhaps in reducing the costs and resource use associated with operating room time and pathologic examination.     

Sentinel lymph node biopsy in breast cancer: an analysis of the maximum number of nodes requiring excision

Sentinel lymph node biopsy (SNB) is now the standard of care in assessment of patients with clinically staged T1-2, N0 breast cancers. This study investigates whether there is a maximum number of sentinel lymph nodes (SLN) that need to be excised without compromising the false-negative (FN) rate of this procedure. Data were prospectively collected for 319 patients undergoing SNB between February 2001 and December 2006 at our institution. This data were analysed, both in terms of the order of SLN retrieval and relative isotope counts of the SLNs, in order to determine the maximum number of SLNs that need to be retrieved without increasing the FN rate. Furthermore, we investigated the relationship between SLN blue dye concentration and the presence of SLN metastases. The SLN identification rate was 97% with no false-negative cases amongst patients undergoing simultaneous axillary clearance historically during technique validation. In patients with SLN metastases, excision of the first 4 SLNs encountered results in the identification of a metastatic SLN in all cases. Although the majority (86%) of SNB metastases are in the hottest node, the SLN containing the metastasis is in the first 4 hottest nodes in 99% of patients with nodal metastases. The remaining 1% of SLN metastases were identified by blue dye. There was no statistically significant association between the SLN blue dye concentration and the presence of SLN metastases. A policy to remove a maximum of four blue and/or hot SLNs along with any palpably abnormal lymph nodes does not result in an increased false-negative rate of detection of SLN metastases.     

Size of sentinel node metastases predicts other nodal disease and survival in malignant melanoma

BACKGROUND: A positive sentinel lymph node (SLN) biopsy is an indication for completion lymph node dissection (CLND) in malignant melanoma; however, most CLNDs are negative. We hypothesized SLN metastatic size of < or =2 mm would predict CLND status and prognosis. METHODS: We evaluated 80 consecutive patients undergoing CLND for positive SLNs over a 10-year period. Incidence of positive nonsentinel nodes and survival were compared for patients with SLN metastases < or =2 mm and >2 mm. RESULTS: Of 504 patients undergoing SLN biopsy, 49 patients had SLN deposits < or =2 mm and a 6% incidence of positive CLNDs. Five-year survival was 85%, essentially the same as negative SLN biopsies. In contrast, 31 had SLN metastases >2 mm, a 45% incidence of addition disease at CLND, and 5-year survival of 47% (P < .0001). CONCLUSION: An SLN metastatic cut point of 2 mm is an efficient predictor of CLND status and survival in malignant melanoma.     

Selective sentinel lymphadenectomy for malignant melanoma

To date, selective sentinel lymphadenectomy (SSL) should be considered a standard approach for staging patients with primary invasive melanoma greater than or equal to 1 mm. It is imperative that the multidisciplinary team master the techniques of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and postoperative pathologic evaluation of the sentinel lymph nodes (SLNs). A SLN is defined as a blue, "hot", or any subsequent lymph node greater than 10% of the in vivo count of the hottest lymph node and as an enlarged or indurated lymph node. Frozen sections are not recommended. For extremity melanoma, delayed SSL may be performed. Preoperative lymphoscintigraphy for extremity melanoma may be done the night before so that surgery can be scheduled as the first case of the following day. Every surgeon who uses blue dye should be cognizant of the potential adverse reaction to isosulfan blue and treatment for such a potential fatal reaction. A complete lymph node dissection is done if the SLN is found to be positive. Elective lymph node dissection should not be done if SSL can be done as a staging procedure. It is important for investigators involved with SSL to follow the clinical outcome of their patients so that the role of SSL can be further defined.     

Histological Features of Melanoma Sentinel Lymph Node Metastases Associated with Status of the Completion Lymphadenectomy and Rate of Subsequent Relapse

Background The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a completion lymph node dissection (CLND). This study sought to define a population of SLN-positive patients, based on their histological pattern of SLN metastases, who may not require CLND. Methods All patients with SLN-positive cutaneous melanoma who underwent CLND between March 1999 and December 2004 at a single academic institution were enrolled. Metastatic deposits in the SLN were categorized by their histological zone of involvement (subcapsular, parenchymal and/or sinusoidal). Logistic regression was used to examine the effect of SLN zone, size of nodal metastases, and other histological factors on CLND positivity. Kaplan-Meier and Cox models were used to study disease recurrence. Results A total of 127 patients were included, and 15.8% had positive non-sentinel nodes. In adjusted analyses, the size of the largest tumor deposit in the SLN was the only factor associated with CLND status. No patients with a tumor deposit ≤0.20 mm had a positive CLND. Although a specific zone of tumor involvement was not predictive of CLND status, involvement of all three zones was independently associated with increased recurrence. Size of the largest tumor deposit was also associated with recurrence, with no recurrences in patients with nodal deposits ≤0.20 mm. Conclusion Histologic features of tumor metastases in positive SLN may be useful in defining a population of patients who may be spared CLND and a group at high risk of recurrence.