Sentinel nodes outside lymph node basins in patients with melanoma

Prognostic Significance and Management of Sentinel Nodes in the Triangular Intermuscular Space of Patients with Melanoma

BACKGROUND

The clinical significance of sentinel nodes (SNs) in the triangular intermuscular space (TIS) of patients with melanoma is poorly understood. This study aimed to determine their incidence and positivity rate, and to report their management and patient outcomes.

METHODS

This was a single-institution retrospective cohort study of patients with unilateral or bilateral TIS SNs on lymphoscintigraphy treated between 1992 and 2017. Recurrence-free survival was analyzed.

RESULTS

Lymphoscintigraphy identified TIS SNs in 266 patients. They were bilateral in 17 patients. Of the 2296 patients with a melanoma on the upper back, 259 (11%) had TIS SNs. Procurement of SNs was not attempted in 122 (43%) of the 283 cases and failed in 11 cases (7%). An SN was successfully retrieved from the TIS in 145 patients (53%) and contained metastasis in 18 of 150 TIS SNs. This was the only positive SN in 12 patients (8%), upstaging all of them. Of the 18 patients with a positive SN in the TIS, 9 (50%) underwent completion axillary lymph node dissection, but no additional involved nodes were found in any of these patients. Recurrence in the TIS was observed in six patients (5%), none of whom had their TIS SN surgically pursued previously.

CONCLUSIONS

Lymphoscintigraphy showed TIS SNs in 11% of patients with melanomas on their upper back. In such cases, retrieval of TIS SNs is required for accurate staging and to minimize the risk of TIS recurrence.

Subcostal lymph nodes: An unusual sentinel lymph node basin in cutaneous melanoma

BACKGROUND AND OBJECTIVES

Lymphatic drainage from subcostal nodes, along the costal groove, have not previously been characterized as sites for melanoma drainage and metastasis. This study reports a series of patients with subcostal nodes draining primary melanomas, with characterization of the sites of primary melanomas that drain to these nodes.

METHODS

Patients who presented to our institution between 2005 and 2020 with documented cutaneous melanoma and sentinel lymph node biopsy of a subcostal node (sentinel = S), or metastases to subcostal nodes later in clinical management (recurrent = R) were included. Patient demographics, melanoma pathology, nodal features, imaging information, surgical approaches, and outcomes data were collected.

RESULTS

Six patients had subcostal sentinel nodes (SNs). Primary sites included the posterior trunk and lateral chest wall. Subcostal nodes were found under ribs 10-12. Subcostal SNs had at least one dimension measuring 3 mm or less. There were no surgical complications related to removing the subcostal SN.

CONCLUSIONS

Melanoma can metastasize to subcostal lymph nodes and be found at the time of SN biopsy or identified at recurrence. These small nodes are fed by lymphatic channels that run in the neurovascular bundle under the ribs. When lymphatic mapping identifies a subcostal SN, it should be excised.

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.

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.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma: Standard and New Technical Procedures and Clinical Advances. A Systematic Review of the Literature

Melanoma is an important public health problem, and its incidence is increasing worldwide. The disease status of regional lymph nodes is the most important prognostic factor in early-stage melanoma patients. Sentinel lymph node biopsy (SLNB) was introduced in the early 1990s as a less invasive procedure than complete lymph node dissection to allow histopathologic evaluation of the "sentinel lymph node" (SLN), which is the first node along the lymphatic pathway from a primary tumor. Sentinel lymph node biopsy has minimal complication risks compared with standard complete lymph node dissection. Currently, SLNB is the accepted method for staging patients with clinically node-negative cutaneous melanoma and provides the most powerful prognostic information by evaluating the nodal basin status. The current practice of SLNB consists of the injection of Tc-labeled radiopharmaceutical, preoperative lymphoscintigraphy with the possibility of using the SPECT/CT hybrid imaging, and intraoperative SLN localization using a handheld gamma probe with or without the use of blue dye. Recently, the SLN localization and detection have been enhanced with the use of new tracers and new intraoperative devices, which have demonstrated to be particularly useful in melanomas of the head and neck region and in area of complex anatomy. Despite these important advances in the technology and the increasing experience in SLN mapping, major research centers have reported a false-negative rate higher than 15%. This relatively high false-negative rate, greater than those reported in the initial validation studies, points out the importance for the nuclear medicine community to continuously improve their knowledge on the biological behavior of melanoma and to improve the technical aspects that may allow more precise staging. For the SLNB procedure to be accurate, it is of critical importance that all "true" SLNs are identified and removed for examination. The aim of this article is to provide general information about the SLNB procedure in clinical practice highlighting the importance of standardization and accuracy of SLN identification in the light of the most recent technical innovations.

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.

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.

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.

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.

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.

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.

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.

A triangular intermuscular space sentinel node in melanoma: association with axillary lymphatic drainage

BACKGROUND

Large centers have described triangular intermuscular space (TIS) sentinel nodes (SNs) for some melanomas of the back. However, their management remains controversial and poorly characterized, especially as related to the ipsilateral axillary node basin. The aim of this study was to summarize our experience with TIS SN, which may contribute to defining their appropriate surgical management.

METHODS

We performed a retrospective review on surgical patients from January 1993 to April 2009. Among 293 patients with upper back melanoma, data were collected on those with TIS SN.

RESULTS

Fourteen patients (5%) with melanoma of the upper back had a TIS SN, 6 of whom (43%) were incorrectly identified at lymphoscintigraphy as axillary, and 11 of whom (79%) had a concurrent axillary SN. Micrometastatic disease was identified in TIS SN in two patients (14%) and in an axillary SN in one (9%). We found direct lymphatic drainage independently to the TIS and to the axilla, as well as a more typical pattern of drainage first to the TIS node and then to axillary nodes.

CONCLUSIONS

We defined three patterns of lymphatic drainage to TIS and axillary nodes. The TIS and axilla are anatomically linked; patients with SN in both locations should undergo biopsies of both for optimal nodal staging. We recommend directed evaluation for TIS SN in patients with upper back melanomas and recommend clearing the TIS at the time of TIS SN biopsy. Melanoma can metastasize to TIS SN, and we discuss considerations for management of the axilla in patients with positive TIS nodes.

Mid-humeral sentinel lymph node dissection in patients with primary cutaneous malignant melanoma

In rare cases, lymphatic drainage from the malignant melanomas in the upper extremity may follow an unpredictable pattern (outside the axillary nodes), and these aberrant sentinel nodes may represent the only site of regional lymph node metastases. The precise anatomical landmarks and technical aspects of surgical exploration of these aberrant sentinel lymph nodes are rarely described in the literature, including aberrant sentinel mid-humeral lymph nodes. This report describes a step-by-step dissection of the mid-humeral sentinel lymph nodes in two patients with a primary malignant melanoma in the upper extremity, identified by lymphatic mapping. Recognition of precise regional anatomy and following a special surgical technique makes the procedure safe and successful, thus avoiding local complications and allowing a prompt recovery.

In-transit sentinel nodes must be found: implication from a 10-year follow-up study in melanoma

The aim was to study the occurrence of in-transit nodes at a preoperative lymphoscintigraphy for patients with primary melanoma, and to reveal their potential role in prognosis. From 1984 to 1996, 911 patients, hospitalized for wide excision of a clinically localized primary cutaneous head-neck or truncal melanoma, had a static lymphoscintigraphy on the day before surgery as part of a prospective protocol. Lymph nodes were in no case removed at the time of scintigraphy. Recurrence and survival patterns were compared for patients with in-transit nodes with the remaining patients with only regional nodes. Follow-up time was a minimum of 10 years. In-transit nodes were visualized by lymphoscintigraphy in 6% of the patients, 18% of whom had a later recurrence in this region. The melanomas in the in-transit node group were slightly thicker, and ulceration was slightly more frequent (neither significant). The in-transit node group had significantly more lymph node basins visualized at scintigraphy compared with the remaining group of patients with only regional nodes. The risk of recurrence and/or death from melanoma was significantly worse (P<0.05) in the in-transit node group compared with the remaining patients. The clinical significance of the in-transit nodes, occasionally seen in melanoma patients (also in stage Ia), may suggest a slightly poorer prognosis and a substantial risk of a later recurrence in the in transit region. We therefore recommend that in-transit nodes must be found and examined exactly as is done with locoregional sentinel nodes.

Diagnosis and treatment of interval sentinel lymph nodes in patients with cutaneous melanoma

BACKGROUND

Interval sentinel lymph nodes in patients with melanoma are occasionally found outside conventional nodal basins. In this study, the authors examined the frequency, location, and incidence of nodal metastasis of such interval nodes in a large cohort of patients with primary cutaneous melanoma.

METHODS

Between September of 1997 and February of 2003, 374 consecutive patients at the Yale Cancer Center Melanoma Unit underwent sentinel lymph node biopsy for primary cutaneous melanoma with a Breslow thickness of at least 1.0 mm and/or Clark IV or greater histologic dermal invasion. All patients underwent preoperative lymphoscintigraphy to map the lymphatic drainage for the primary lesion and intraoperative confirmation, and biopsy was performed on all sentinel lymph nodes identified.

RESULTS

Unequivocal interval sentinel lymph nodes were identified in eight of 374 patients (2.1 percent). Three of these eight patients had metastatic spread to the interval sentinel nodes. In four of the eight patients, the interval sentinel lymph node was not located in the anticipated lymphatic pathway between the primary tumor and the sentinel lymph node basin.

CONCLUSIONS

Interval sentinel nodes seem as likely to contain micrometastatic disease as those in the expected sentinel lymph node basin. Half of the subjects displayed interval sentinel lymph nodes that were not in the anticipated lymphatic pathway between the primary tumor and the sentinel lymph node basin. These findings suggest that adequate preoperative lymphoscintigraphy and intraoperative recognition of interval nodes are of paramount importance in the treatment of melanoma.

Case of metastatic melanoma in an epitrochlear lymph node arising in a pregnant woman

We describe a rare case of metastatic melanoma in an epitrochlear lymph node in a 29-year-old female patient. The patient had been aware of a brown macule on her right posterior forearm at puberty. Because the lesion had enlarged rapidly, she was referred to our hospital. Histological examination revealed a malignant melanoma. She underwent wide local excision with 3-cm margins and split thickness skin graft closure, but we were not able to perform sentinel node biopsy. She also received three cycles of systemic chemotherapy with dacarbazine, nimustine, vincristine and interferon-beta. However, an epitrochlear node (interval node) metastasis occurred during pregnancy (seventh week) 2 years after the operation. We emphasize that it is important for clinicians to pay attention to the possibility of epitrochlear node metastasis in patients with malignant melanoma in the upper extremity and that it is necessary to perform sentinel node biopsy to identify uncommon lymph node metastasis.

Popliteal lymphadenectomy on sentinel lymph node melanoma metastasis

Popliteal lymph node dissection is a procedure that surgeons rarely perform and, therefore, scarcely represented in bibliography. In this paper we present the case of a patient with melanoma metastasis to popliteal sentinel lymph nodes showing the surgical procedure and discussing some epidemiological and technical issues.

Implications of Popliteal Lymph Node Detected by Sentinel Lymph Node Biopsy

BACKGROUND

Although there is lymphatic flow into the popliteal fossa from a skin tumor located in the lower leg, popliteal metastasis is extremely rare. Recently, sentinel lymph nodes outside traditional nodal basins have been identified. This study investigated the incidence of sentinel nodes in the popliteal region and the indication for biopsy.

METHODS

Fourteen patients with various skin cancers involving the lower extremities (nine melanomas, four squamous cell carcinomas, and one sweat gland carcinoma) underwent lymphoscintigraphy and excision with sentinel lymph node biopsy.

RESULTS

In all 14 patients, hot spots showed accumulation in the groin region. Five of 14 patients (36%) demonstrated popliteal sentinel nodes in addition to the inguinal nodes. Three of five popliteal sentinel nodes were histologically studied. A patient with acral melanoma demonstrated micrometastasis of melanoma cells in a popliteal node but not in the groin node.

CONCLUSION

This study demonstrates that sentinel lymph nodes located in the popliteal fossa are frequently detected by lymphoscintigraphy and that biopsy should be performed if popliteal nodes are identified.

Single-Institution Experience in the Management of Patients with Clinical Stage I and II Cutaneous Melanoma: Results of Sentinel Lymph Node Biopsy in 240 Cases

BACKGROUND

Lymphatic mapping and sentinel lymph node biopsy (SLNB) has been developed as a minimally invasive technique to determine the pathologic status of regional lymph nodes in patients without clinically palpable disease and incorporated in the latest version of the American Joint Committee on Cancer (AJCC) staging system for cutaneous melanoma.

OBJECTIVE

To analyze the results of SLNB and the prognostic value of the micrometastases and the pattern of early recurrences in patients according to sentinel lymph node (SLN) status.

METHOD

Patients with cutaneous melanoma in stages I and II (AJCC 2002) who underwent lymphatic mapping and SLNB from 1997 to 2003 were included in a prospective database for analysis.

RESULTS

The rate of identification of the SLN was 100%. Micrometastases to SLN were found in 20.8% of patients. The rate of SLN micrometastases increased according to Breslow thickness and clinical stage. Breslow thickness of 0.99 mm was the optimal cutpoint for predicting the SLNB result. Twenty-four patients (12.3%) developed a locoregional or distant recurrence at a median follow-up of 31 months. Recurrences were more frequent in patients with a positive SLN. Among patients who had a recurrence, those with a positive SLN were more likely to have distant metastases than those with negative SLN. Nodal recurrences were more frequent in patients with a negative SLN compared with those with a positive SLN.

CONCLUSIONS

The status of the SLN provides accurate staging for identifying patients who may benefit from further therapy and is the most important prognostic factor of relapse-free survival.

[Anatomical location of the primary tumor as a variable to be considered in sentinel node biopsy of cutaneous melanoma]

INTRODUCTION

The anatomical location of cutaneous melanoma has been suggested to be an independent prognostic factor. The aim of the present study was to determine whether the location of the primary tumor influences sentinel node detection in cutaneous melanoma.

PATIENTS AND METHOD

Two hundred twelve patients with primary cutaneous melanoma (96 of the limbs, 89 of the trunk and 27 of the head or neck) who underwent sentinel lymph node biopsy were studied. Adequate lymphoscintigraphic and surgical localization was evaluated and epidemiological and histopathological variables, the number of lymph nodes draining the site of the primary lesion, sentinel nodes per drainage basin, and tumor-positive nodes were compared.

RESULTS

Localization was less successful for tumors of the head and neck (88.8%), both with lymphoscintigraphy (P<.001) and surgery (P<.0005), especially for lymph nodes adjacent to salivary glands (P<.0005). Melanomas of the trunk showed a greater number of nodes per lesion and wider variability in drainage pathways (P<.0005), although there were no differences in the number of sentinel nodes per drainage basin (P=.455).

CONCLUSIONS

Sentinel node detection with less successful in cutaneous melanomas located in the head and neck. Location of the sentinel node adjacent to a salivary gland is a factor that influences its detection. Cutaneous melanomas of the trunk showed a higher number of draining nodes per lesion than those located in the limbs or head and neck.

Prepubic Sentinel Node Location in Penile Carcinoma

An unusual sentinel node location in a patient with penile carcinoma is described. The preoperative lymphoscintigram showed a prepubic sentinel node. The node could be harvested during surgery. This case illustrates one of the advantages of lymphatic mapping in penile carcinoma: preoperative lymphoscintigraphy can identify lymph nodes outside the usual nodal basins.

Sentinel node biopsy procedures with an analysis of recurrence patterns and prognosis in melanoma patients: technical advantages using computer-assisted gamma probe with adjustable collimation

The purpose of this study was to investigate whether a computer-assisted gamma probe with adjustable collimation could aid in the detection of sentinel nodes (SNs) and to analyse the patterns of recurrence and prognosis in SN-positive and SN-negative cases. We analysed 385 SN biopsies. The SN identification rate was 87.2% using preoperative lymphoscintigraphy and blue dye, 93.9% using preoperative lymphoscintigraphy, blue dye and different probes, and 100% using preoperative lymphoscintigraphy, blue dye and a computer-assisted probe with adjustable collimation. The computer-assisted probe was particularly advantageous in cases where the melanoma was located very close to the SN and in cases of deep-seated nodes or nodes with low uptake, due to the possibility of changing the collimation during the procedure. The SN-positive rate according to the thickness of the primary melanoma was 1.7% for melanomas < or = 1 mm in thickness and 27.5% for melanomas > or = 1 mm. In 4.9% of cases we identified nodes outside the regional nodal basin. In one case we found a micrometastasis in a blue and hot interval node of the lateral abdominal wall. Analysing the node counts registered by the computer-assisted probe, we verified that the blue-positive node for tumour metastases was not the most radioactive node in the field in six out of 52 positive cases (11.5%). Distant metastases were present in 2.0% of SN-negative patients, and in 24% of SN-positive patients (P < 0.001). Highly statistically significant differences were found between SN-negative and SN-positive patients in both the 3 year disease-free survival (86.3% versus 49.2%) and the 3 year disease-specific survival (92.3% versus 77.1%) (P < 0.001).

Lessons learned from the Sunbelt Melanoma Trial

The Sunbelt Melanoma Trial is an ongoing multicenter prospective randomized trial that involves 79 centers and over 3600 patients from across the United States and Canada. This is one of the first large randomized studies to incorporate molecular staging using reverse transcriptase polymerase chain reaction (RT-PCR). While the results related to the primary endpoints of the study are not yet available, several analyses have shed light on many aspects of sentinel lymph node (SLN) biopsy and melanoma prognostic factors. In particular, we have developed a practical definition of sentinel nodes based on the degree of radioactivity. We have established the low rate of postoperative complications associated with SLN biopsy as compared to complete lymph node dissection. We have identified factors that predict the presence of SLN metastases. In contrast, we have been unable to identify factors that indicate a low risk of non-sentinel node metastases in patients with a positive sentinel node, suggesting that completion lymphadenectomy is appropriate for such patients. We have further established the value of identifying interval or in-transit sentinel nodes, which can be the only site of nodal metastasis. We have evaluated the particular challenges associated with SLN biopsy of head and neck melanomas, have evaluated the patterns of early recurrence, and have identified an interesting correlation between increasing patient age and a number of prognostic factors. Future analyses will evaluate the benefit of early therapeutic lymphadenectomy and early institution of adjuvant interferon alfa-2b therapy, as well as the validity of molecular staging.

Sentinel lymph node biopsy progress in surgical treatment of cancer

BACKGROUND

Forty-three years after the first description of the sentinel lymph node technique in malignant tumours of the parotid by Gould, sentinel lymph node biopsy (SNLB) has become a precious tool in the treatment of solid tumours.

METHODS

In the following review we give a synopsis of the fundamentals of the sentinel lymph node concept and then proceed to an overview of recent advances of SNLB in gastrointestinal cancers.

RESULTS

In some tumour entities, SNLB has been shown to reflect reliably the lymph node status of the tumour-draining lymph node basin. In melanoma and breast cancer, it became a widely accepted element of the routine surgical management of these malignant diseases. In gastrointestinal tumours, the technique is currently under intense investigation. First reports on its application in other solid tumours, such as non-small cell lung cancer, thyroid carcinoma, oropharyngeal carcinoma, vulvar carcinoma, and Merckel cell carcinoma of the skin, were published more recently.

CONCLUSION

SNLB has become an important component of diagnosis and treatment of solid tumours. A growing number of publications on SNLB in gastrointestinal cancer documents the interest of many investigators in the application of this technique in this tumour entity. As long as imaging techniques like 18FDG PET or other molecular imaging techniques are limited by their spatial resolution, SNLB remains the technique of choice for lympho-nodal staging.

Correlation between preoperative lymphoscintigraphy and metastatic nodal disease sites in 362 patients with cutaneous melanomas of the head and neck

OBJECTIVE

Lymphoscintigraphy for head and neck melanomas demonstrates a wide variation in lymphatic drainage pathways, and sentinel nodes (SNs) are reported in sites that are not clinically predicted (discordant). To assess the clinical relevance of these discordant node fields, the lymphoscintigrams of patients with head and neck melanomas were analyzed and correlated with the sites of metastatic nodal disease.

METHODS

In 362 patients with head and neck melanomas who underwent lymphoscintigraphy, the locations of the SNs were compared with the locations of the primary tumors. The SNs were removed and examined in 136 patients and an elective or therapeutic regional lymph node dissection was performed in 40 patients.

RESULTS

Lymphoscintigraphy identified a total of 918 SNs (mean 2.5 per patient). One or more SNs was located in a discordant site in 114 patients (31.5%). Lymph node metastases developed in 16 patients with nonoperated SNs, all underneath the tattoo spots on the skin used to mark the position of the SNs. In 14 patients SN biopsy revealed metastatic melanoma. After a negative SN biopsy procedure 11 patients developed regional lymph node metastases during follow-up. Elective and therapeutic neck dissections demonstrated 10 patients with nodal metastases, all located in predicted node fields. Of the 51 patients with involved lymph nodes, 7 had positive nodes in discordant sites (13.7%).

CONCLUSIONS

Metastases from head and neck melanomas can occur in any SN demonstrated by lymphoscintigraphy. SNs in discordant as well as predicted node fields should be removed and examined to optimize the accuracy of staging.

Radioguided sentinel lymph node biopsy in patients with malignant cutaneous melanoma: the nuclear medicine contribution

As for other solid tumors, malignant cutaneous melanoma drains in a logical way through the lymphatic system, from the first to subsequent levels. Therefore, the first lymph node encountered (the sentinel node) will most likely be the first to be affected by metastasis, and a negative sentinel node makes it highly unlikely that other nodes in the same lymphatic basin are affected. Sentinel lymph node biopsy distinguishes patients without nodal metastases, who can avoid nodal basin dissection with its associated risk of lymphedema, and those with metastatic involvement who might benefit from additional therapy. This procedure represents a significant advantage as a minimally invasive procedure, considering that only an average 20% of melanoma patients with Breslow thickness between 1.5 and 4 mm harbour metastasis in their sentinel node(s) and are therefore candidates to elective lymph node dissection procedures. The cells that originate cutaneous melanomas are located between dermis and epidermis, a zone that drains to the inner lymphatic network in the reticular dermis, in turn to larger collecting lymphatics in subcutis. Therefore, the optimal modality of interstitial administration of radiocolloids for lymphoscintigraphy and subsequent radioguided sentinel lymph node biopsy is through intradermal/subdermal injection. (99m)Tc-labeled colloids in various size ranges are equally adequate for radioguided sentinel lymph node biopsy in patients with cutaneous melanoma, depending on local experience and availability. For melanomas located in the midline area of the head, neck, and trunk, particular consideration should be given to ambiguous lymphatic drainage, which frequently requires interstitial administration virtually all around the tumor or surgical scar from prior excision of the melanoma. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy because images are used to direct the surgeon to the sites of the node(s). The sentinel lymph node should have a significantly higher count than that of background (at least 10:1 intraoperatively). After removal of the sentinel node, the surgical bed must be reexamined to ensure that all radioactive sites are identified and removed for analysis. The success rate of radioguidance in localizing the sentinel lymph node in melanoma patients is about 98% in institutions where a high number of procedures are performed, approaching 99% when combined with the vital blue dye technique. The procedure is becoming the standard of care for patients with cutaneous melanoma because of its high prognostic value that has led to include the procedure in the most recent version of the TNM staging system.

Controversies in the management of metastatic melanoma to regional lymphatic basins

The primary management of lymph nodes involved with metastatic melanoma is regional lymphadenectomy. Many controversies of regional lymph node dissection exist including extent and nature of the lymphadenectomy, treatment of lymphatic metastases in unusual locations and the role of adjuvant radiotherapy. Although radical neck dissection has been the gold standard for cervical disease, modified dissections do not seem to compromise regional control in appropriately selected patients. In the axilla, a Level I, II, and III dissection is most commonly performed. Combined superficial and deep groin dissection is justified for clinically palpable disease although management of patients with histologically positive yet clinically non-palpable disease is more controversial. Burden of disease, imaging, patient co-morbidity, and Cloquet nodal status must be considered. Many technical variations exist in an attempt to improve morbidity rates secondary to lymphadenectomy. Unfortunately, complication rates are difficult to compare secondary to variable study designs, definitions, and patient populations. Adjuvant radiation therapy appears warranted in patients with high risk of regional recurrence including bulky disease, extracapsular extension or cervical location.

Is sentinel node biopsy beneficial in melanoma patients? A report on 200 patients with cutaneous melanoma

AIM

The aim of this study was to evaluate the reliability and clinical impact of sentinel node biopsy, including preoperative lymphoscintigraphy and intraoperative lymphatic mapping in patients with cutaneous melanoma of the head, neck, trunk or extremities.

METHODS

Two hundred patients (103 women, 97 men), median age 57 (range 21-86) years with cutaneous melanoma > or =1.0mm Breslow thickness and clinically negative lymph nodes participated in a single institutional prospective study from May 1995 to January 2000. Primary melanoma sites included: 22 head and neck (11%), 67 trunk (34%), 29 upper extremity (14%) and 82 lower extremity (41%). The median Breslow thickness was 2.5 (range 1.0-20.0)mm. Preoperative dynamic and static lymphoscintigraphy, intraoperative blue dye and a gamma detection probe were used. If histological examination with HE or IHC showed metastases, therapeutic lymph node dissection (TLND) was performed.

RESULTS

Sentinel node(s) could be identified in 197 patients (99%); 393 sentinel nodes (mean: 2.0 per patient, range 1-7) were removed from 241 basins. Three procedures failed in the head and neck region. In 167 patients, the sentinel nodes were both blue and radioactive (85%); in 26 patients, they were only radioactive (13%) and in four patients only blue (2%). In total, 150 patients had tumour-negative sentinel nodes (76%). During a median follow-up of 47 (range 24-79) months, nodal recurrence in a negative mapped basin was documented in six patients of which isolated recurrence was in two patients and recurrence together with locoregional recurrence in four patients (false negative rate 6/54=11%). Estimated three-year recurrence-free survival in the node-negative patients and node-positive patients was 83 and 66% respectively (P<0.05). The overall survival at three years was 92 and 73% respectively (P<0.05).

CONCLUSION

Sentinel node biopsy provides accurate staging and important prognostic information. The final place of sentinel node biopsy is still undefined, and therefore sentinel node biopsy is still considered as an experimental surgical staging procedure.

Implications of lymphatic drainage to unusual sentinel lymph node sites in patients with primary cutaneous melanoma

BACKGROUND

Sentinel lymphadenectomy reliably identifies the first site(s) of regional lymphatic drainage and, therefore, the most likely lymph nodes to contain occult metastasis in patients with primary cutaneous melanoma. Although in most patients lymphatic drainage from the primary melanoma first reaches a standard lymph node basin, a sentinel lymph node (SLN) may be identified in an unusual location. The objective of this study was to determine the frequency and significance of unusual sentinel lymph node drainage patterns in a large cohort of patients with primary melanoma.

METHODS

The records of 1145 consecutive primary melanoma patients who underwent SLN biopsy were reviewed. Preoperative lymphoscintigraphy was performed in all patients with truncal melanoma and in many patients with distal extremity lesions. Unusual lymph node sites were defined as epitrochlear, popliteal, or ectopic/interval (in-transit or any other nonstandard lymph node-bearing area).

RESULTS

At least one SLN was harvested in 1117 patients (98%). SLN biopsy of an unusual lymph node site was attempted in 59 patients (5%). Successful intraoperative localization and biopsy was performed in 54 (92%) of 59 patients for a total of 56 unusual sites. Of these, 7 (13%) were popliteal, 8 (14%) were epitrochlear, and 41 (73%) were ectopic/interval. Preoperative lymphoscintigraphy was performed in 41 of these 54 patients and correctly identified unusual SLN locations in 12 (29%); the majority of unusual SLNs were identified only with the assistance of the intraoperative gamma probe. In four patients (7%), the unusual lymph node site was the only site from which SLNs were harvested. In the remaining 50 patients (93%), biopsies were performed on SLNs from both unusual sites and from a standard lymph node basin. Among the 54 patients who underwent a SLN biopsy of an unusual nodal site, 7 (13%) had lymph node metastases in that location. In four of the seven patients, the only positive SLN was from the unusual site.

CONCLUSIONS

Sentinel lymphatic drainage patterns include lymph node-bearing areas that may be outside established standard lymph node basins and may represent the only site of regional lymph node metastases. Although preoperative lymphoscintigraphy may assist in the identification of unusual SLN drainage patterns, intraoperative use of the gamma probe is recommended to identify accurately and completely all sites of regional lymph node drainage.

Update on the use of sentinel node biopsy in patients with melanoma: who and how

This review highlights the utility of sentinel lymph node biopsy for melanoma. The histopathologic status of the sentinel lymph node is acknowledged as the most powerful indicator of prognosis. Changes by the American Joint Committee for Cancer have not only incorporated the importance of ulceration in cutaneous melanoma, but have focused on the number of metastatic lymph nodes as well as whether the disease is macro- or micrometastatic. Specific technical aspects of the sentinel lymph node procedure are discussed, with emphasis on practical guidelines to minimize incorrect nodal staging.