Interval nodes: the forgotten sentinel nodes in patients with melanoma

Interval Sentinel Lymph Nodes With the Use of Routine Lymphoscintigraphy in Extremity Melanoma

INTRODUCTION

Lymphoscintigraphy (LS) helps identify drainage to interval (epitrochlear or popliteal) lymph node basins for extremity melanomas. This study evaluated how often routine LS evaluation identified an interval sentinel lymph node (SLN) and how often that node was found to have metastasis.

METHODS

A single institution, retrospective study identified patients with an extremity melanoma who underwent routine LS and SLN biopsy over a 25-y period. Comparisons of factors associated with the identification of interval node drainage and tumor status were made.

RESULTS

In 634 patients reviewed, 5.7% of patients drained to an interval SLN. Of those biopsied, 29.2% were positive for micrometastases. Among patients with biopsies of both the traditional and interval nodal basins, nearly 20% had positive interval nodes with negative SLNs in the traditional basin. Sex, age, thickness, ulceration, and the presence of mitotic figures were not predictive of identifying an interval node on LS, nor for having disease in an interval node. Anatomic location of the primary melanoma was the only identifiable risk factor, as no interval nodes were identified in melanomas of the thigh or upper arm (P ≤ 0.001).

CONCLUSIONS

Distal extremity melanomas have a moderate risk of mapping to an interval SLN. Routine LS should be considered in these patients, especially as these may be the only tumor-positive nodes. However, primary extremity melanomas proximal to the epitrochlear or popliteal nodal basins do not map to interval nodes, and improved savings and workflow could be realized by selectively omitting routine LS in such patients.

Imaging Assessment of Interval Metastasis from Melanoma

Interval metastasis is a particular metastatic category of metastatic localizations in the lymph nodes in patients with melanoma. Interval nodes are generally located at nonregional lymphatic stations placed along the pathway of the spread of melanoma, such as the epitrochlear lymph node station, the popliteal fossa, and the retroareolar station. Imaging techniques for evaluation of patients with interval metastasis from melanoma diseases include ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), lymphoscintigraphy (LS), and positron emission tomography (PET). A literature review was conducted through a methodical search on the Pubmed and Embase databases. The evaluation of lymph node metastases represents a critical phase in the staging and follow-up of melanoma patients. Therefore, a thorough knowledge of the imaging methods available and the interactions between the clinician and the radiologist are essential for making the correct choice for individual patients, for a better management, and to improve treatment and survival.

The Use and Technique of Sentinel Node Biopsy for Skin Cancer

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the indications for and prognostic value of sentinel lymph node biopsy in skin cancer. 2. Learn the advantages and disadvantages of various modalities used alone or in combination when performing sentinel lymph node biopsy. 3. Understand how to perform sentinel lymph node biopsy in skin cancer patients.

SUMMARY

Advances in technique used to perform sentinel lymph node biopsy to assess lymph node status have led to increased accuracy of the procedure and improved patient outcomes.

Analysis of the Different Lymphatic Drainage Patterns during Sentinel Lymph Node Biopsy for Skin Melanoma

In the last two decades, studies of lymphoscintigraphy imaging in lymphatic mapping reported an extreme heterogeneity of skin lymphatic drainage of some skin area, in contrast with the previous scientific literature. The aim of this study was to investigate the presence of any correlations between the topographical location of cutaneous melanoma and the topographical location of sentinel lymph nodes. Data from 165 patients undergoing sentinel lymph node biopsy between January 2013 and May 2021 were analyzed, demonstrating that melanomas in the Lumbar region presented a significant more heterogeneous drainage by site than those in the Scapular region (p < 0.01) and that melanomas in the Subscapular region were significantly more heterogeneous by laterality (unilateral vs. bilateral) than those in the Scapular region (p < 0.05). Results of this study supported the evidence of multiple lymphatic drainage as regards the sentinel node biopsy performed in skin melanoma located on the dorsal subscapular region and lumbar region. For this reason, the association of preoperative lymphoscintigraphy with another imaging evaluation is needed in these critical cutaneous areas. Recent technical developments enabling fluorescence lymphography together with indocyanine green have significantly improved the visualization of lymphatic drainage patterns at a microscopic level. In the preoperative phase, any doubt can be resolved by associating the SPET-CT scan to lymphoscintigraphy, while during the intraoperative phase, an additional evaluation with indocyanine green can be performed in doubtful cases. The aim of the duplex lymphatic mapping (pre and/or intraoperative) is an accurate search of sentinel nodes, in order to reduce the rate of false negatives.

Is skipped nodal metastasis a phenomenon of cutaneous melanoma?

BACKGROUND AND METHODS

Skipped nodal metastasis (SNM) is a recognized phenomenon of visceral cancers when metastases bypass the regional basin and skip to a distant nodal basin without evidence of distant metastases. Its occurrence is undocumented in cutaneous melanoma patients but of potential prognostic significance. We therefore assessed the frequency of SNM in a large series of patients with limb melanomas.

PATIENTS AND METHODS

We studied melanoma patients attending a tertiary oncology hospital in northwest England using two approaches. First, we systematically searched medical records of an unselected patient sample treated 2002-2015, and second, we studied lymphoscintigrams of all patients with limb melanoma who underwent sentinel node biopsy 2008-2019.

RESULTS

Of 672 melanoma patients whose clinical records were examined, 16 had regional nodal metastases without apparent visceral spread and one appeared to have SNM but further scans were uncovered that showed concurrent pulmonary metastases. Of 667 limb melanoma patients with lymphoscintigrams, 7 showed dual lymphatic drainage patterns to distal as well as regional nodal basins, but none had micro-metastases solely in the distant basin.

CONCLUSION

Occurrence of SNM in cutaneous melanoma is highly unlikely.

Lymphatic Mapping and Sentinel Lymph Node Biopsy in the Management of Primary Cutaneous Melanoma: Report of a Single-centre Experience

Aims and Background

Lymphatic mapping and sentinel lymph node biopsy provide important prognostic data in patients with early stage melanoma and are crucial in guiding the management of the tumor. We report our experience with lymphatic mapping and sentinel lymph node biopsy in a group of patients with primary cutaneous melanoma and discuss recent concepts and controversies on its use.

Patients and Methods

A total of 111 patients with stage I-II AJCC primary cutaneous melanoma underwent lymphatic mapping and sentinel lymph node biopsy from December 1999 through December 2004 using a standardized technique of preoperative lymphoscintigraphy and biopsy guided by blue dye injection in addition to a hand-held gamma probe. After removal, sentinel lymph nodes were submitted to serial sectioning and permanent preparations for histological and immunohistochemical examination. Complete lymph node dissection was performed only in patients with tumor-positive sentinel lymph nodes.

Results

Sentinel lymph nodes were identified and removed in all patients (detection rate of 100%), and metastases were found in 17 cases (15.3%). The incidence of metastasis in sentinel lymph nodes was 2.1%, 15.9%, 35.2%, and 41.6% for melanomas < or 1.0, 1.01-2.0, 2.01-4.0, and > 4.0 mm in thickness, respectively. Complete lymph node dissection was performed in 15 of 17 patients with positive sentinel lymph nodes, and metastases in non-sentinel lymph nodes were detected in only 2 cases (11.7%). Recurrences were more frequently observed in patients with a positive than in those with negative sentinel lymph node (41.1% vs 5.3% at a median follow-up of 31.5 months, P<0.001). The false-negative rate was 2.1%.

Conclusions

Our study confirms that lymphatic mapping and sentinel lymph node biopsy allow accurate staging and yield relevant prognostic information in patients with early stage melanoma.

Sentinel Lymph Node Biopsy and Complete Lymph Node Dissection for Melanoma

Purpose of Review

The main surgical treatment for invasive malignant melanoma consists of wide surgical and examination of the sentinel node and in selected cases complete lymph node dissection. The aim of this review is to present data for the optimal surgical management of patients with malignant melanoma.

Recent Findings

A surgical excision margin of 1–2 cm is recommended for invasive melanoma depending on the thickness of the melanoma. Sentinel node biopsy may be considered for patients with at least T1b melanomas thickness 0.8 to 1.0 mm or less than 0.8 mm Breslow thickness with ulceration, classified as T1b lesion, per recent AJCC guidelines. Two randomized controlled trials have been published—DeCOG (German Dermatologic Cooperative Oncology Group Selective Lymphadenectomy) and MSLT-2 (Multicenter Selective Lymphadenectomy Trial) comparing the complete lymph node dissection (CLND) with observation after positive sentinel node biopsy. In the MSLT-2 study, the disease control rate was improved in the immediate CLND group compared with observation but there was no difference in 3-year melanoma specific survival (86% ± 1.3% and 86% ± 1.2%, respectively; p = 0.42). Isolated limb perfusion (ILP) or isolated limb infusion (ILI) with melphalan and actinomycin D is recommended for large and multiple in-transit metastases and satellite metastases in the extremities when local excision is considered ineffective or too extensive.

Summary

In light of new adjuvant treatment options and new indications for checkpoint inhibitors, and the lack of survival benefit after CLND, we can expect open surgery to decrease in melanoma disease.

Melanoma & nuclear medicine: new insights & advances

The contribution of nuclear medicine to management of melanoma patients is increasing. In intermediate-thickness N0 melanomas, lymphoscintigraphy provides a roadmap for sentinel node biopsy. With the introduction of single-photon emission computed tomography images with integrated computed tomography (SPECT/CT), 3D anatomic environments for accurate surgical planning are now possible. Sentinel node identification in intricate anatomical areas (pelvic cavity, head/neck) has been improved using hybrid radioactive/fluorescent tracers, preoperative lymphoscintigraphy and SPECT/CT together with modern intraoperative portable imaging technologies for surgical navigation (free-hand SPECT, portable gamma cameras). Furthermore, PET/CT today provides 3D roadmaps to resect 18F-fluorodeoxyglucose-avid melanoma lesions. Simultaneously, in advanced-stage melanoma and recurrences, 18F-fluorodeoxyglucose-PET/CT is useful in clinical staging and treatment decision as well as in the evaluation of therapy response. In this article, we review new insights and recent nuclear medicine advances in the management of melanoma patients.

Surgical management of tumor-positive interval node in melanoma patients: An observational study

The presence of interval nodes (IN) in melanoma is testified in several studies and sometimes these lymph nodes can contain metastatic disease. Currently there are no guidelines about the management of patients with tumor-positive INs.We enrolled all patients affected by melanoma who underwent sentinel lymph node biopsy (SLNB) in a single institution. All patients with tumor-positive IN underwent the lymphadenectomy of the subsequent draining lymphatic field. Prognosis of IN+-patients was compared with subjects with positive SLNB in usual field through Kaplan-Meier and multivariate Cox regression analysis.Overall 596 subjects underwent lymphoscintigraphy and one or more INs were identified in 94 (15.8%) patients. The mean number of sentinel lymph nodes (SNs) identified per patient was significantly higher in patients with INs. Macrometastasis were more common in patients with INs. Matched pair analysis testified a statistically significant better prognosis in patients with positive-INs when compared with patients with positive SNs in usual side with the same demographic and clinical characteristics. These findings were confirmed both in analysis of 10-year recurrence-free period, then in 10-years overall survival analysis.Lymphadenectomy of the lymphatic draining field beyond positive-IN testify has proved to be a safe procedure that may improve prognosis in melanoma patients with tumor-positive INs. The better prognosis of patients with tumor-positive INs undergoing lymphadenectomy may be justified by the earlier treatment of lymphatic metastases. Further multicentric comparative studies are needed to evaluate possible impact of this procedure on prognosis of melanoma patients.

In transit sentinel node drainage as a prognostic factor for patients with cutaneous melanoma

BACKGROUND

Minor basin or in transit node drainage can be found in patients with cutaneous melanoma who undergo sentinel node biopsy. Its clinical impact is still unclear. Our objective is to evaluate clinical outcomes in patients who presented with in transit sentinel node (ITN) drainage.

MATERIAL AND METHODS

Retrospective analysis of patients who underwent sentinel node biopsy (SNB) in a single Brazilian institution between 2000 and 2015.

RESULTS

Our cohort comprised 1223 SNB. There were 64 patients (5.2%) with ITN. Melanoma of the limbs (OR 10.61, P < 0.0001) and acral subtype (OR 3.49, P < 0.0001) were associated with ITN drainage. Among these 64 patients, 14 (21.9%) had a positive SNB. The ITN was positive for metastases in five patients, four in a popliteal basin and one on the trunk. Regarding completion node dissection (CND), two patients had positive non-sentinel nodes (NSN), both in major basins. In patients who developed recurrence, time to recurrence was shorter (mean time 18 vs 31.4 months, P = 0.001) and time to death was shorter (mean time 31.6 vs 40 months, P = 0.039) in those who had ITN drainage.

CONCLUSION

ITN drainage was associated with earlier recurrences and deaths from melanoma.

Prognostic Role of Multiple Lymphatic Basin Drainage in Sentinel Lymph Node-Negative Trunk Melanoma Patients: A Multicenter Study from the Italian Melanoma Intergroup

BACKGROUND

Multiple lymphatic basin drainage (MLBD) is frequently observed in patients with trunk melanoma undergoing sentinel lymph node (SLN) biopsy. Conflicting data regarding the prognostic association of MLBD in SLN-negative patients have been reported. This study aimed to investigate the prognostic role of MLBD in patients with negative SLN biopsy.

METHODS

Retrospective data from 656 melanoma patients who underwent a SLN biopsy (1991-2012) at six Italian centers were gathered in a multicenter database. MLBD was defined as lymphoscintigraphic and intraoperative identification of an SLN in more than one nodal basin. Clinical and pathologic variables were recorded and analyzed for their impact on survival.

RESULTS

SLN-negative patients with MLBD were at lower risk of melanoma recurrence [hazard ratio (HR) 0.73, P = 0.05) and melanoma-related death (HR 0.68, P = 0.001) independent of common staging features. Multivariable Cox analyses of disease-free interval (DFI) and disease-specific survival (DSS) showed that MLBD maintained a favorable role and ulceration an unfavorable role. Histologic regression was independently associated only with DFI. When survival was stratified according to presence of MLBD, histologic regression and Breslow thickness <2 mm were associated with improved DFI (5-year DFI: 96.9 vs. 66,1 %, respectively; HR 0.48, P < 0.001) and DSS (5-year DSS: 96.7 vs. 71.8 %, respectively; HR 0.52, P = 0.005) compared to patients without these three favorable parameters.

CONCLUSIONS

Patients with negative SLN biopsy results have better prognosis when two or more lymphatic basins are identified and analyzed. Further research is required to investigate the mechanisms behind this evidence.

Intraoperative mapping of sentinel lymph node metastases using a clinically translated ultrasmall silica nanoparticle

The management of regional lymph nodes in patients with melanoma has undergone a significant paradigm shift over the past several decades, transitioning from the use of more aggressive surgical approaches, such as lymph node basin dissection, to the application of minimally invasive sentinel lymph node (SLN) biopsy methods to detect the presence of nodal micrometastases. SLN biopsy has enabled reliable, highly accurate, and low-morbidity staging of regional lymph nodes in early stage melanoma as a means of guiding treatment decisions and improving patient outcomes. The accurate identification and staging of lymph nodes is an important prognostic factor, identifying those patients for whom the expected benefits of nodal resection outweigh attendant surgical risks. However, currently used standard-of-care technologies for SLN detection are associated with significant limitations. This has fueled the development of clinically promising platforms that can serve as intraoperative visualization tools to aid accurate and specific determination of tumor-bearing lymph nodes, map cancer-promoting biological properties at the cellular/molecular levels, and delineate nodes from adjacent critical structures. Among a number of promising cancer-imaging probes that might facilitate achievement of these ends is a first-in-kind ultrasmall tumor-targeting inorganic (silica) nanoparticle, designed to overcome translational challenges. The rationale driving these considerations and the application of this platform as an intraoperative treatment tool for guiding resection of cancerous lymph nodes is discussed and presented within the context of alternative imaging technologies. WIREs Nanomed Nanobiotechnol 2016, 8:535-553. doi: 10.1002/wnan.1380 For further resources related to this article, please visit the WIREs website.

Interval sentinel lymph nodes in melanoma: a digital pathology analysis of Ki67 expression and microvascular density

The presence of interval sentinel lymph nodes in melanoma is documented in several studies, but controversies still exist about the management of these lymph nodes. In this study, an immunohistochemical evaluation of tumor cell proliferation and neo-angiogenesis has been performed with the aim of establishing a correlation between these two parameters between positive and negative interval sentinel lymph nodes. This retrospective study reviewed data of 23 patients diagnosed with melanoma. Bioptic specimens of interval sentinel lymph node were retrieved, and immunohistochemical reactions on tissue sections were performed using Ki67 as a marker of proliferation and CD31 as a blood vessel marker for the study of angiogenesis. The entire stained tissue sections for each case were digitized using Aperio Scanscope Cs whole-slide scanning platform and stored as high-resolution images. Image analysis was carried out on three selected fields of equal area using IHC Nuclear and Microvessel analysis algorithms to determine positive Ki67 nuclei and vessel number. Patients were divided into positive and negative interval sentinel lymph node groups, and the positive interval sentinel lymph node group was further divided into interval positive with micrometastasis and interval positive with macrometastasis subgroups. The analysis revealed a significant difference between positive and negative interval sentinel lymph nodes in the percentage of Ki67-positive nuclei and mean vessel number suggestive of an increased cellular proliferation and angiogenesis in positive interval sentinel lymph nodes. Further analysis in the interval positive lymph node group showed a significant difference between micro- and macrometastasis subgroups in the percentage of Ki67-positive nuclei and mean vessel number. Percentage of Ki67-positive nuclei was increased in the macrometastasis subgroup, while mean vessel number was increased in the micrometastasis subgroup. The results of this study suggest that the correlation between tumor cell proliferation and neo-angiogenesis in interval sentinel lymph nodes in melanoma could be used as a good predictive marker to distinguish interval positive sentinel lymph nodes with micrometastasis from interval positive lymph nodes with macrometastasis subgroups.

EANM practice guidelines for lymphoscintigraphy and sentinel lymph node biopsy in melanoma

PURPOSE

Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized melanoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with melanoma.

METHODS

These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, national nuclear medicine societies, the European Society of Surgical Oncology (ESSO) and the European Association for Research and Treatment of Cancer (EORTC) melanoma group. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).

CONCLUSION

The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of melanoma patients.

Contribution of dynamic sentinel lymphoscintigraphy images to the diagnosis of patients with malignant skin neoplasms in the upper and lower extremities

The aim of the present study was to confirm the contribution of dynamic images in sentinel lymphoscintigraphy in malignant skin neoplasms: precisely, to investigate if dynamic images were necessary and to observe if dynamic images could reduce the areas needed for biopsy and dissection. Twenty-five patients with malignant skin neoplasms of the lower (n = 21) and upper (n = 4) extremities were retrospectively investigated. Images were evaluated by two independent reviewers, an expert in diagnostic radiology and nuclear medicine and a diagnostic radiologist in training. Visualized hot spots were assessed to be sentinel nodes using only static planar images. Next, both static planar and dynamic images were assessed. Reviewers scored diagnostic confidence values of determined sentinel nodes as follows: 0, cannot be decided; 1, possible; 2, probable; and 3, definitive. Patterns of lymphatic drainage were categorized into six different pathways: (1) inguinal type, (2) popliteal type, (3) inguinal and popliteal type, (4) axillary type, (5) cubital type, and (6) axillary and cubital type. In cases in the lower extremities, with dynamic images, the expert reviewer changed assessment in three cases and the trainee reviewer changed it in one case. There were no cases in which a decision was changed to be the same between both reviewers. Although the average diagnostic confidence value of assessment is usually higher with dynamic images, significant differences were not present. In cases of the upper extremities, both reviewers changed their assessment in one patient. By mutual agreement, cases in which assessment was changed with dynamic images were the inguinal and popliteal type, and the axillary and cubital type. The expert reviewer noticed lymphatic channels only visualized on dynamic images and changed assessment. Determination of whether or not a lymph node is a sentinel node depends on visualization of the lymphatic network. In the present circumstances, all biopsies of hot spots determined to be lymph nodes should not be excluded. However, excessive biopsies should be avoided as much as possible. It is necessary to use dynamic images alongside skillful observation.

Melanoma and nuclear medicine

Supported by a large body of published work, the contribution of nuclear medicine technologies to the assessment of melanoma has been increasing in recent years. Lymphoscintigraphy-assisted sentinel lymph node biopsy and PET are in continuous evolution with the aid of technological imaging advances, making it possible to fuse functional and anatomic images (e.g., with SPECT/CT, PET/CT and 3D rendering systems). The development of hybrid fluorescent-radioactive tracers that enable high-quality preoperative lymphoscintigraphy and SPECT/CT, and the optimization of modern intraoperative portable imaging technologies, such as free-hand SPECT and portable γ-cameras, are important innovations that have improved sentinel lymph node identification in complex anatomical areas, such as the pelvis and head and neck. Concurrently, ¹⁸F-fluorodeoxyglucose-PET has proved its usefulness in the clinical staging and treatment decision-making process, and there is also emerging evidence regarding its utility in the evaluation of therapeutic response. The potential uses of other novel PET radiotracers could open up a new field of use for this technique. In this article, we review the current and future role of nuclear medicine in the management of melanoma.

Surgical management of sentinel lymph node biopsy outside major nodal basin in patients with cutaneous melanoma

PURPOSE

To assess the incidence of nonmajor lymphatic basin sentinel nodes in patients with cutaneous melanoma in order to propose a correct nomenclature and inform appropriate surgical management.

METHODS

This was a retrospective review of 1,045 consecutive patients with cutaneous melanoma who underwent sentinel lymph node biopsy and dynamic lymphoscintigraphy to identify sentinel node site. Nonmajor drainage sites were classified as uncommon (located in a minor lymphatic basin along the lymphatic drainage to a major classical nodal basin) or interval (located anywhere along the lymphatics between the primary tumor site and the nearest lymphatic basin) sentinel nodes.

RESULTS

Nonclassical sentinel nodes were identified in 32 patients (3.0 %). Uncommon sentinel nodes were identified in 3.2 % (n = 17) of trunk melanoma primary disease and in 1.5 % (n = 7) of upper and lower extremity sites. Interval sentinel nodes were identified in 1.3 % (n = 7) of trunk primary lesions, with none from upper and lower extremities melanomas. The incidence of tumor-positive sentinel nodes was 24.1 % (245 of 1,013) in classical sites and 12.5 % (4 of 32) in uncommon/interval sites.

CONCLUSIONS

The definition of uncommon and interval sentinel nodes allows the identification of different lymphatic pathways and inform appropriate surgical treatment. Wider experience with uncommon/interval sentinel nodes will better clarify the clinical implications and surgical management to be adopted in the management of uncommon and interval sentinel node sites.

Lymphoscintigraphy in clinical routine practice: reproducibility and accuracy in melanoma patients with a long-term follow-up

INTRODUCTION

The sentinel node status is the most important single factor determining overall survival for patients with localized melanoma. Preoperative lymphoscintigraphy (LS) is essential in locating the correct sentinel lymph node (SN) and the reproducibility of the method determines the accuracy of the sentinel node biopsy (SNB). This study aims at determining the reproducibility and accuracy of LS in routine clinical practice after long-term follow-up.

PATIENTS AND METHODS

One hundred and eight melanoma patients with clinically unpredictable lymphatic drainage were prospectively enrolled to undergo two LS. The first LS was performed to determine the site and number of the lymphatic basins to plan SNB anesthesia and the second preoperative LS was to allow SN localization intra-operatively.

RESULTS

Lymphatic drainage was demonstrated in all patients. In 84 of 108 cases, both LSs were concordant in terms of site and number of nodal basins visualized. After a median follow-up of 80 months, no nodal recurrence was observed in the five patients with a decreased number of lymph node basins. In the group with increased number of lymph node basins, one patient developed nodal metastases in the same regional lymph node basin visualized by both LS studies.

CONCLUSION

LS is an accurate and reproducible method to determine the localization of the sentinel node in the day-to-day routine to clinical practice when primary melanoma is also located in body sites with variable lymphatic drainage.

Long-term treatment outcome after only popliteal lymph node dissection for nodal metastasis in malignant melanoma of the heel: the only "interval node" dissection can be an adequate surgical treatment

We present a patient with malignant melanoma on his heel. Wide local excision was performed, along with sentinel lymph node biopsy of the inguinal and popliteal lesions. The primary site was clear of tumor at all margins; the inguinal nodes were negative, but the popliteal node was positive for metastatic melanoma. Only radical popliteal lymph node dissection was performed. The patient went on to receive adjuvant chemoimmunotherapy. There was no recurrence or complication until the long-term followup. Popliteal drainage from below the knee is uncommon, and the rate of popliteal-positive and inguinal-negative cases is estimated to be less than 1% of all melanomas. There is no established evidence about how to treat lymph nodes in these cases. Because we considered popliteal nodes as a regional, not interval, lymph node basin, only popliteal lymph node dissection was performed, and good postoperative course was achieved. The first site of drainage is the sentinel node, and the popliteal node can be a sentinel node. The inguinal node is not a sentinel node in all lower extremity melanomas. This case illustrates the importance of individual detailed investigation of lymphatic drainage patterns from foot to inguinal and popliteal nodes.

Decisive role of SPECT/CT in localization of unusual periscapular sentinel nodes in patients with posterior trunk melanoma: three illustrative cases and a review of the literature

Sentinel node mapping is widely applied in patients with melanoma. Although this type of skin cancer usually drains to the standard regional nodal basins, some patients have drainage to an unpredicted site. Nodes lying along a lymphatic channel, between the primary melanoma site and a common basin, are often called interval, in-transit, ectopic, intercalated, or aberrant nodes. They must be considered sentinel lymph nodes because they receive direct lymphatic drainage from a primary tumor site. Most investigators agree that interval sentinel nodes should be harvested; however, the management of melanoma patients with an involved interval sentinel node without established metastasis in the regional basin downstream is controversial. New and innovating technologies have improved nuclear medicine images, including single-photon emission computed tomography/computed tomography (SPECT/CT), a multimodal technique that fuses the radioactivity distribution detected by SPECT with the anatomic information harvested by CT. SPECT/CT does not replace the conventional planar images; it should be considered as a complementary modality for the search of sentinel lymph nodes. We report three illustrative cases that underline the decisive role of SPECT/CT with two-dimensional and three-dimensional reconstruction images to localize the uncommon periscapular sentinel nodes in patients with melanoma of the posterior trunk. The use of this image fusion technique on these patients leads to improved preoperative visualization of the sentinel nodes, may help identify additional periscapular interval sentinel nodes, and enables precise localization of the nodes with their surrounding anatomic structures. The cases are discussed together with a review of the literature.

Sentinel node studies in truncal melanoma: does an increased number of draining basins correlate with an increased risk of lymph metastasis?

OBJECTIVES

To assess whether an association exists between drainage to multiple basins and lymphatic metastasis in patients with truncal melanoma.

METHODS

We retrospectively reviewed 227 patients with primary malignant melanoma between January 2006 and December 2009. All patients received an intradermal injection of (99m)Tc-nanocolloid and lymphoscintigraphy followed by sentinel node biopsy. Pre-staging histology with Breslow thickness from excision biopsy was also obtained.

RESULTS

82/227 (36%) patients with primary truncal melanoma were identified. Nodal histology was positive for metastatic disease in 27/82 (32.9%) patients. Of these 27, 15 had 1 basin of drainage, 7 had 2 basins of drainage and 5 had 3 basins of drainage. Of the 55 node-negative patients, 35 had 1 basin, 18 had 2 basins and 2 had 3 basins of drainage. We found no significant correlation with sentinel node positivity and those that had ≥2 drainage basins. Breslow thickness was available in 65/82(79.2%) patients. Sentinel node biopsy was positive in 6/28 patients who had <1.5 mm thickness, 8/14 who had a 1.5-3.9 mm thickness and 9/23 who had ≥4 mm thickness. There was a significant correlation between Breslow thickness of ≥4 mm and nodal positivity (P = 0.03).

CONCLUSION

This study demonstrates no association between multiple drainage basins and sentinel node histology. Sentinel lymph node status did correlate with Breslow thickness.

Popliteal node visualization during standard pedal lymphoscintigraphy for a swollen limb indicates impaired lymph drainage

OBJECTIVE

The objective of our study was to examine the frequency and significance of visualization of popliteal nodes during lymphoscintigraphy for the investigation of lower extremity swelling.

MATERIALS AND METHODS

Technetium-99m-labeled nanocolloid was injected subcutaneously in the first web spaces of both feet of 204 consecutive patients (69 males, 135 females; age range, 11-79 years) undergoing routine, clinically indicated lymphoscintigraphy; imaging was performed 5, 45, and 150 minutes after injection. The patients were asked not to undertake any vigorous exercise between the injection and completion of imaging.

RESULTS

No popliteal nodes were visualized in 29 patients in whom there was no evidence of lymphedema on clinical or lymphoscintigraphic examination (group 1). Unilateral or bilateral popliteal nodes were visualized in 10 of 39 patients (25.6%) with clinical evidence of lymphedema but normal lymphoscintigraphy findings (group 2) (p < 0.005 vs group 1). In 136 patients with clinical evidence of lymphedema and abnormal lymphoscintigraphy findings (group 3), unilateral or bilateral popliteal nodes were visualized in 59 (43.4%) (p < 0.0001 vs group 1). Popliteal nodes were visualized in 40 of 73 limbs with "dermal backflow" (54.8%) and 42 of 335 limbs without dermal backflow (12.5%) (p < 0.0001).

CONCLUSION

Popliteal node visualization after subcutaneous foot web space injection is an important sign of abnormal lymphatic function in patients with clinical lymphedema of the lower extremities.

Lymphoscintigraphy defines new lymphatic pathways from cutaneous melanoma site: clinical implications and surgical management

Sentinel lymph node biopsy is commonly applied as staging procedure of regional lymph nodes in patients with cutaneous melanoma. Dynamic lymphoscintigraphy defines the lymphatic pathways from a primary melanoma site and allows to identify the node receiving lymphatic drainage from the primary tumor, which is the sentinel lymph node. In rare cases, lymphoscintigraphy shows sites of lymphatic drainage in nonclassical basins never described in the past when lymphatic drainage was considered only according to the anatomical proximity of the tumor primary site. These peculiar sentinel nodes, so-called "uncommon/interval" nodes, must be surgically removed because they may contain micrometastatic disease and may be the only site of nodal involvement.

Guidelines for lymphoscintigraphy and F18 FDG PET scans in melanoma

Melanoma has a high potential to develop metastases. Accurate staging is essential for appropriate management. Sentinel node (SN) status is a powerful prognostic factor in early stage melanoma. Staging is assisted by SN biopsy after lymphoscintigraphy to locate all true SNs prior to biopsy. PET using F18-FDG can detect metastases and is used to restage patients with AJCC Stages III and IV disease before planning surgery with curative intent.

Pathways for cervical metastasis in malignant neoplasms of the head and neck region

There have been significant changes in the evaluation and management of lymphatic metastases in the neck during the past several decades, and knowledge of the functional anatomy of the cervical lymphatics is fundamental to the clinical management of metastasis in this region. This review provides a comprehensive description of the cervical lymphatics and discusses how this knowledge is used in the modern management of the neck lymphatics in the setting of common cancers of the head and neck. The patterns of tumor spread can be delineated based on the well-studied functional anatomy of the lymphatic networks in the cervical region. The characteristics and patterns of metastatic spread for two common cancers found in this region, squamous cell carcinoma and cutaneous malignant melanoma, are discussed in this review. Significant improvements in clinical care, namely, selective neck dissection and sentinel lymph node biopsy aided by lymphoscintigraphy, have been developed and are based upon detailed studies of the pathways of metastatic spread. These advances have significantly decreased the morbidity associated with the evaluation and treatment of metastatic disease to the neck.

Interval sentinel lymph nodes: an unusual localization in patients with cutaneous melanoma

Background. Recent studies have demonstrated that there exists a great variation in the lymphatic drainage in patients with malignant melanoma. Some patients have drainage to lymph nodes outside of conventional nodal basins. The lymph nodes that exist between a primary melanoma and its regional nodal basin are defined “interval nodes”. Interval node occurs in a small minority of patients with forearm melanoma. We report our experience of the Melanoma Unit of University Hospital Spedali Civili Brescia, Italy. Methods. Lymphatic mapping using cutaneous lymphoscintigraphy (LS) has become a standard preoperative diagnostic procedure to locate the sentinel lymph nodes (SLNs) in cutaneous melanoma. We used LS to identify sentinel lymph nodes biopsy (SLNB) in 480 patients. Results. From over 2100 patients affected by cutaneous melanoma, we identified 2 interval nodes in 480 patients with SLNB . The melanomas were both located in the left forearm. The interval nodes were also both located in the left arm. Conclusion. The combination of preoperative LS and intraoperative hand-held gamma detecting probe plays a remarkable role in identifying these uncommon lymph node locations. Knowledge of the unusual drainage patterns will help to ensure the accuracy and the completeness of sentinel nodes identification.

Sentinel node biopsy for melanoma: an update after two decades of experience

When detected and treated early, melanoma has an excellent prognosis. Unfortunately, as the tumor invades deeper into tissue the risk of metastatic spread to regional lymph nodes and beyond increases and the prognosis worsens significantly. Therefore, accurately detecting any regional lymphatic metastasis would significantly aid in determining a patient's prognosis and help guide his or her treatment plan. In 1991, Don Morton and colleagues presented new paradigm in diagnosing regional lymphatic involvement of tumors termed sentinel lymph node biopsy (SLNB). By mapping the regional lymph system around a tumor and tracing the lymphatic flow, a determination of the most likely lymph node or nodes the cancer will spread to first is made. Then, a limited biopsy of the most likely nodes is performed rather than a more-invasive removal of the entire local lymphatic chain. In 20 years that have followed, a great deal of information has been gained as to its accuracy, prognostic value, appropriate candidates, and its impact on regional disease control and survival. The SLNB has been shown to accurately stage regional lymph node basins in stage I and II melanoma patients with minimal morbidity. More sensitive histologic techniques are now being applied that may allow even greater accuracy in the staging of melanoma patients. Although specific percent risk thresholds are still in question, recommendation for SLNB when melanomas are 1 mm or thicker has gained wide acceptance. SLNB may also be appropriate for patients with melanomas that are between 0.76 and 1 mm thick and have ulceration, high mitotic rates, or reach a Clark level IV. Therefore, melanomas with IB or greater staging should be considered for SLNB.

Management of popliteal sentinel nodes in melanoma

BACKGROUND

Although most melanomas on the distal lower extremity drain exclusively to inguinal lymph nodes, a small percentage (<5%) drain to interval nodes in the popliteal basin. We investigated a possible relationship between tumor-draining popliteal and inguinal nodes in patients with lower-extremity melanoma.

STUDY DESIGN

We queried our melanoma database to identify patients who underwent sentinel node biopsy (SNB) for an infrapopliteal melanoma. Patterns of nodal drainage and nodal metastasis were analyzed.

RESULTS

Of 461 patients who underwent SNB for a primary infrapopliteal melanoma, 15 (3.2%) had drainage to the popliteal basin. Thirteen melanomas were on the posterior leg and foot, and 2 were on the anterior lower leg. Mean Breslow thickness was 2.4 mm. All 15 patients with popliteal drainage also had inguinal drainage and therefore underwent concurrent inguinal and popliteal SNB. The average number of popliteal sentinel nodes was 1.4 (range 1 to 3). Eight patients (53%) had a tumor-positive popliteal sentinel node, and 6 of the 8 underwent completion popliteal lymphadenectomy. Four of the 8 patients (50%) also had tumor-positive inguinal sentinel nodes; all underwent complete inguinal lymphadenectomy. We also identified 9 additional patients who underwent SNB for locoregional recurrent melanomas of the infrapopliteal leg. Three (33%) of these patients had concurrent inguinal and popliteal SNB, with 1 isolated tumor-positive popliteal node found.

CONCLUSIONS

In our series, a high percentage of popliteal sentinel lymph nodes contained metastases, and these patients frequently also had inguinal metastases. In our patients, all inguinal metastases were associated with concomitant popliteal metastases. Although it is anatomically separate, the inguinal basin appears to be a functional extension of the popliteal basin.

Advantages of preoperative ultrasound in conjunction with lymphoscintigraphy in detecting malignant melanoma metastases in sentinel lymph nodes: a retrospective analysis in 221 patients with malignant melanoma AJCC Stages I and II

BACKGROUND

Sentinel lymph node excision (SLNE) for the detection of regional nodal metastases and staging of malignant melanoma has resulted in some controversies in international discussions as it is a surgical intervention with potential morbidity.

OBJECTIVE

The present retrospective study seeks to clarify the reliability of preoperative ultrasonography (US) in direct comparison to the result of SLNE and seeks to identify potential advantages of preoperative ultrasound if performed in conjunction with lymphoscintigraphy in detecting malignant melanoma metastases in sentinel lymph node (SLN).

PATIENTS

We retrospectively analysed data from 221 patients with primary malignant melanoma with a Breslow index of ≥ 1.0 mm.

RESULTS

Of the 221 patients, 77.4% (n = 171) had a negative SLN. In 50 patients (22.6%), the histopathological investigation of 71 excised lymph nodes resulted in a positive SLN. The US examination demonstrated a sensitivity of 13.6%, a specificity of 96.9%, a positive predictive value of 97.2% and a negative predictive value of 12.6%. SLNE alone shows a sensitivity of 94%, a specificity of 98.6%, a positive predictive value of 100% and a negative predictive value of 98.3%. Preoperative US in conjunction with dynamic lymphoscintigraphy, followed by SLNE, demonstrated a detecting ratio of 100% (n = 28) for micrometastases and 98.6% (n = 42/43) for macrometastases.

CONCLUSION

In conclusion, this study confirms that preoperative US alone cannot replace the vital information obtained during dynamic lymphoscintigraphy. But preoperative US is an important component of the staging procedure in melanoma patients and has clear advantages when performed in conjunction with dynamic lymphoscintigraphy. Therefore, we recommend preoperative US before every SLNE.

Nuclear Medicine in Early-Stage Melanoma: Sentinel Node Biopsy-FDG-PET/CT

Sentinel node status is the most powerful prognostic factor in patients with early-stage melanoma. This review discusses several issues of clinical interest and technical points for an optimized sentinel node biopsy (SNB) procedure. The role of fluorodeoxyglucose positron emission tomography/computed tomography is clearly established in patients with suspicion of locoregional or distant recurrence of melanoma before any surgical decision. However, its role at initial staging or follow-up of patients with localized disease or with positive SNB is less clear. Further research and efforts should focus on identifying which groups of patients are at specific high risk of early distant recurrence.

Features predicting sentinel lymph node positivity in Merkel cell carcinoma

PURPOSE

Merkel cell carcinoma (MCC) is a relatively rare, potentially aggressive cutaneous malignancy. We examined the clinical and histologic features of primary MCC that may correlate with the probability of a positive sentinel lymph node (SLN).

METHODS

Ninety-five patients with MCC who underwent SLN biopsy at the University of Michigan were identified. SLN biopsy was performed on 97 primary tumors, and an SLN was identified in 93 instances. These were reviewed for clinical and histologic features and associated SLN positivity. Univariate associations between these characteristics and a positive SLN were tested for by using either the χ(2) or the Fisher's exact test. A backward elimination algorithm was used to help create a best multiple variable model to explain a positive SLN.

RESULTS

SLN positivity was significantly associated with the clinical size of the lesion, greatest horizontal histologic dimension, tumor thickness, mitotic rate, and histologic growth pattern. Two competing multivariate models were generated to predict a positive SLN. The histologic growth pattern was present in both models and combined with either tumor thickness or mitotic rate.

CONCLUSION

Increasing clinical size, increasing tumor thickness, increasing mitotic rate, and infiltrative tumor growth pattern were significantly associated with a greater likelihood of a positive SLN. By using the growth pattern and tumor thickness model, no subgroup of patients was predicted to have a lower than 15% to 20% likelihood of a positive SLN. This suggests that all patients presenting with MCC without clinical evidence of regional lymph node disease should be considered for SLN biopsy.

Epitrochlear lymph nodes: Anatomy, clinical aspects, and sonography features. Pictorial essay()

The normal and abnormal aspects of the epitrochlear lymphatic station are not well known, mainly because the axillary basin is commonly regarded as the primary lymphatic target of all upper limb disorders. The purpose of this paper is to illustrate, through a review of specific cases, the normal and abnormal findings that can emerge during ultrasonographic (US) and color-Doppler US exploration of the epitrochlear region. We illustrate the normal anatomy and variations of the epitrochlear lymph nodes and highlight the functional role of this lymphatic station. Subsequently we describe the US and color-Doppler US findings. A number of different abnormalities are reviewed, including metastases (mainly from upper limb cutaneous melanomas), Hodgkin disease, and non-Hodgkin lymphoma, lymphadenitis (cat-scratch disease, foreign bodies, and IV drug abuse). Measures are suggested to avoid interpretative pitfalls and to carry out an effective differential diagnosis of elbow masses. This article represents a pictorial essay of the US and color-Doppler US features of various epitrochlear lymph node abnormalities that clinicians may not be familiar with.

Interval sentinel lymph nodes in patients with cutaneous melanoma: a single-institution study in Japan

Interval sentinel lymph nodes (ISLN) are defined as the lymph nodes located between the primary melanoma and anatomically well-defined lymph nodal basins. It was reported that the ISLN appeared to be at the same metastatic risk as sentinel lymph nodes (SLN) in the traditional nodal basins. This study aimed to examine the incidence and metastatic risk of the ISLN in melanoma patients. Between June of 1999 and December of 2008, 117 patients enrolled at Nagoya University Hospital underwent SLN biopsy for primary cutaneous melanoma with a Breslow thickness of at least 1.0 mm. Triple techniques with lymphoscintigraphy, blue dye injection and gamma probe were used for the biopsy except for 13 cases that underwent lymphoscintigraphy, ultrasonography and blue dye injection, but without gamma probe. Patients who had melanoma of the head and neck were excluded from this analysis. The SLN were identified in 253 nodal basins from 117 patients, and ISLN were found in six patients (5%). We recognized 41 (17%) SLN metastases in 246 conventional nodal basins and one (14%) in seven ISLN. Although ISLN were identified infrequently, the incidence of metastasis into the ISLN was similar to that into SLN in conventional nodal basins. It is therefore recommended that preoperative lymphoscintigraphy and intraoperative recognition of ISLN should be performed.

Management of the difficult sentinel lymph node in patients with primary cutaneous melanoma

Sentinel lymph nodes (SLNs) are examined for occult melanoma metastases for accurate staging to dictate optimal therapy. The aim of this case series was to discuss clinical challenges in SLN biopsy. Ten challenging cases were identified from over 700 melanoma patients with SLN biopsy for primary cutaneous melanoma at the Yale Cancer Center Melanoma Unit. These cases were complicated by issues of (1) visualization of SLN, (2) concurrent and topographically close melanomas, (3) aberrant lymphatic drainage outside standard basins, (4) altered lymphatic drainage secondary to surgery, and (5) access to SLN. This case series identifies complex clinical scenarios encountered with SLN biopsy that should be familiar to a surgeon involved in the surgical care of melanoma patients.

Joint practice guidelines for radionuclide lymphoscintigraphy for sentinel node localization in oral/oropharyngeal squamous cell carcinoma

Involvement of the cervical lymph nodes is the most important prognostic factor for patients with oral/oropharyngeal squamous cell carcinoma (OSCC), and the decision whether to electively treat patients with clinically negative necks remains a controversial topic. Sentinel node biopsy (SNB) provides a minimally invasive method of determining the disease status of the cervical node basin, without the need for a formal neck dissection. This technique potentially improves the accuracy of histological nodal staging and avoids over-treating three-quarters of this patient population, minimizing associated morbidity. The technique has been validated for patients with OSCC, and larger-scale studies are in progress to determine its exact role in the management of this patient population. This article was designed to outline the current best practice guidelines for the provision of SNB in patients with early-stage OSCC, and to provide a framework for the currently evolving recommendations for its use. These guidelines were prepared by a multidisciplinary surgical/nuclear medicine/pathology expert panel under the joint auspices of the European Association of Nuclear Medicine (EANM) Oncology Committee and the Sentinel European Node Trial Committee.

Sonography for locoregional staging and follow-up of cutaneous melanoma: how we do it

OBJECTIVE

Sonography is being used with increasing frequency in the assessment of locoregional tumor spread in patients with melanoma. Nevertheless, to maximize its practical impact, sonography should be performed with state-of-the-art equipment, by specifically trained operators, and using a careful exploration technique and well-defined diagnostic criteria. In this "how I do it"-type article, we illustrate our practical approach to sonography of cutaneous melanoma.

METHODS

We first illustrate the basic and advanced technical requirements; then we describe our exploration methods and our image interpretation approach; and finally, we report on our use of sonography as a guidance tool for interventional procedures. Special emphasis is given to methodological and interpretative clues, tricks, and pitfalls.

RESULTS

Sonography can be used in the initial staging of patients with melanoma, particularly in the screening of patients scheduled for a sentinel lymph node biopsy procedure. Additionally, sonography can be used during patient follow-up to detect locoregional recurrence earlier than palpation.

CONCLUSIONS

Sonography plays a growing role in the assessment of the superficial spread of melanoma. Nevertheless, state-of-the-art equipment and careful exploration by trained operators are necessary.

Mid-arm lymph nodes dissection for melanoma

An interval node in the upper limb termed the mid-arm node was recently identified. However, its surgical anatomy remains unclear. We report a patient with metastatic melanoma of the mid-arm node and the epitrochlear node at 10 years after removal of the primary tumour from the forearm and therapeutic axillary lymph node dissection. The mid-arm node is located halfway up the upper arm on the medial intermuscular septum, at the site where the brachial vessels, the median nerve and the ulnar nerve run adjacent to each other. The mid-arm node lies adjacent to the basilic vein where lymphatic vessels ascend and converge. This is the first report regarding the surgical anatomy of the mid-arm node.