Intraoperative lymphatic mapping and sentinel lymph node biopsy for Merkel cell carcinoma

BACKGROUND: Merkel cell carcinoma is a rare cutaneous neoplasm which commonly spreads to the regional lymph nodes. The feasibility of identifying the sentinel node in patients with clinically node-negative Merkel cell carcinoma was evaluated. METHODS: Sentinel lymphatic mapping was performed in 18 patients with stage 1 Merkel cell carcinoma using the combination of isosulphan blue dye and 99mTc-radiolabelled sulphur colloid. Patients with tumour metastasis in the sentinel node underwent complete dissection of the remainder of the lymph node basin. RESULTS: Eighteen patients underwent removal of 35 sentinel nodes. Two patients demonstrated metastatic disease in the sentinel lymph nodes; complete dissection of the involved nodal basin revealed no additional positive nodes suggesting that the sentinel lymph node had been identified. The node-negative patients received no further surgical therapy, with no evidence of recurrent disease in the sentinel nodal basin at a median of 7 months' follow-up. CONCLUSION: Sentinel node biopsy is feasible in patients with Merkel cell carcinoma. It can be used to stage patients and provides important prognostic information. In those with subclinical nodal disease, it may direct early regional lymphadenectomy but the effect of such surgery on survival remains unclear.     

Cutaneous Lymphatic Drainage in Patients With Grossly Involved Nodal Basins

Background: The development of lymphatic mapping techniques has facilitated the identification of the sentinel lymph node (SLN), the first node in the regional basin into which cutaneous lymphatics flow from a particular skin area. Previous studies have shown that SLN histology reflects the histology of the entire basin, because melanoma metastases progress in an orderly fashion, involving the SLN before higher nodes in the basin become involved with metastatic disease. It is uncertain whether these orderly cutaneous lymphatic flow patterns are maintained in grossly involved basins. Lymphatic mapping was performed in a population of melanoma patients with clinically palpable lymphadenopathy to address this question. We aimed to determine whether the presence of gross nodal disease in the basin alters lymphatic flow into that basin so that lymphatic mapping techniques are not applicable, and, in patients referred with a grossly involved basin, whether preoperative lymphoscintigraphy should be performed to identify other regional basins at risk for metastases.Methods: Eight patients presented with grossly palpable disease in the regional basin and underwent preoperative lymphoscintigraphy. All patients with palpable disease and all basins indicated by lymphoscintigraphy to be at risk were dissected. Three patients presented with clinically palpable nodes at the time of diagnosis, and five developed nodal disease on clinical follow-up after undergoing initial wide local excision only. A total of 10 basins in the eight patients were dissected. Of these, eight of the basins had grossly palpable regional nodal disease, and the other two basins were identified by preoperative lymphoscintigraphy as being at risk for metastases. The SLN was identified with intraoperative mapping, harvested, and submitted to pathology. Complete therapeutic lymph node dissections were performed following the SLN harvest in the basins with grossly palpable disease. SLN biopsy alone was performed in the two basins that did not have clinically palpable adenopathy but showed cutaneous lymphatic flow from the scintigram.Results: Sixteen SLNs were harvested from these eight basins with grossly palpable disease, and 14 (87.5%) contained tumor. In each case, one of the SLNs was the grossly palpable node, and in six of the basins (75%) it was the only site of melanoma metastases. An additional 190 higher level, non-SLNs were removed, 32 (16.8%) of which contained microscopic foci of metastatic melanoma (P = .015). The null hypothesis that melanoma nodal metastasis is a random event is rejected. Two patients with trunk melanoma primary sites were identified to have other basins at risk for metastatic disease on lymphoscintigraphy. SLN biopsies were performed in these two patients, and one had microscopic nodal disease in the SLN.Conclusions: These data support the fact that cutaneous lymphatic drainage patterns are maintained in patients with grossly involved basins, thus buttressing the idea that the SLN is the node most likely to develop metastatic disease. Gross disease in the basin does not significantly alter cutaneous lymphatic flow into the regional basin, as the sentinel lymph node identified under these circumstances is the same as with the grossly involved node. Preoperative lymphoscintigraphy in patients who present with grossly involved nodes in one basin may identify other regional basins with micrometastatic disease and deserves further study in this setting.     

Lymphatic mapping with sentinel node biopsy in pediatric patients

BACKGROUND/PURPOSE: Lymphatic mapping with sentinel node biopsy is used widely in adult melanoma and breast cancer to determine nodal status without the morbidity associated with elective lymph node dissection. This technique can be used in children to determine lymph node status with limited dissection and accurate interpretation. The authors report their initial experience. METHODS: The charts of patients who underwent lymphatic mapping with sentinel node biopsy were reviewed retrospectively. Lymphoscintigraphy was performed in patients with truncal lesions 24 hours before surgery to determine the draining nodal basin (for surgical mapping). The tumors were injected 1 hour preoperatively with technetium sulfur colloid and in the operating room with Lymphazurin blue. The draining basin was examined using a radioisotope detector. The blue nodes with high counts were localized and removed. If nodal metastases were identified, lymph node dissection was recommended. Four patients were injected only with Lymphazurin blue. RESULTS: Thirteen children (7 girls, 6 boys; mean age, 7 years) underwent lymphatic mapping with sentinel node biopsy. The tumor types were as follows: 8 malignant melanoma (6 extremity, 2 truncal), 1 malignant peripheral nerve sheath tumor, 1 alveolar soft part sarcoma, and 3 rhabdomyosarcoma. A mean of 2.4 nodes (range, 1 to 6) were removed from each patient. Six patients had a positive sentinel node. Formal lymph node dissection was performed on 4 of the 6 patients, 1 of whom had further nodal disease with 2 of 13 nodes containing micrometastases. One of the 6 patients refused lymph node dissection and adjuvant therapy; the final patient had rhabdomyosarcoma, a malignancy for which lymph node dissection is not indicated. Pulmonary metastasis developed 26 months after diagnoses in the patient with alveolar soft part sarcoma and a negative sentinel node. This patient was injected only with Lymphazurin blue at the time of sentinel node biopsy and refused adjuvant therapy. There have been no other recurrences. There were no complications related to lymphatic mapping or sentinel node biopsy. CONCLUSIONS: Lymphatic mapping with sentinel node biopsy, using both technetium-labeled sulfur colloid and Lymphazurin blue, can be performed safely in pediatric skin and soft tissue malignancies. Further study with long-term follow-up will determine the utility and accuracy of this technique in pediatric malignancies.     

Sentinel Lymph Node Biopsy for Patients With Cutaneous Desmoplastic Melanoma

Background: Although desmoplastic melanoma (DM) often presents at a locally advanced stage, nodal metastases are rare. We describe our experience with lymphatic mapping and sentinel lymph node biopsy (SLNB) in patients with DM to characterize the biological behavior of these tumors.Methods: Twenty-seven patients with cutaneous DM underwent wide excision and attempted SLNB between 1996 and 2001. All pathology was reviewed by a single dermatopathologist (KB). Clinical and histological features were recorded.Results: There were 20 male and 7 female patients. The median age was 64 years (range, 35–83 years). The head and neck was the most commonly involved anatomical region (n = 14). The median Breslow thickness was 2.2 mm. Twenty-four patients underwent successful SLNB. No patient had a positive sentinel node. At a median follow-up of 27 months, five patients recurred (four systemic and one local); all five had undergone successful SLNB. Two of these patients died of disease, two are alive with disease, and one remains alive and disease free. No patient experienced failure in a regional nodal basin.Conclusions:DM is a biologically distinct form of melanoma, with a very low incidence of regional lymph node metastases, either at presentation or in long-term follow-up. This biology should be considered when designing rational treatment strategies for these patients.     

Lymphoscintigraphy and sentinel node biopsy accurately stage melanoma in patients presenting after wide local excision

Background: Patients have traditionally been considered candidates for sentinel node biopsy (SNBx) only at the time of wide local excision (WLE). We hypothesized that patients with prior WLE may also be staged accurately with SNBx.Methods: Seventy-six patients, including 18 patients from the University of Virginia and 58 from a multicenter study of SNBx led by investigators at the University of Vermont, who had previous WLE for clinically localized melanoma underwent lymphoscintigraphy with SNBx. Median follow-up time was 38 months.Results: Intraoperative identification of at least 1 sentinel node was accomplished in 75 patients (98.6%). The mean number of sentinel nodes removed per patient was 2.0. Eleven patients (15%) had positive sentinel nodes. Among the 64 patients with negative SNBx, 3 (4%) developed nodal recurrences in a sentinel node–negative basin simultaneous with systemic metastasis, and 1 (1%) developed an isolated first recurrence in a lymph node.Conclusions:This multicenter study more than doubles the published experience with SNBx after WLE and provides much-needed outcome data on recurrence after SNBx in these patients. These outcomes compare favorably with the reported literature for patients with SNBx at the time of WLE, suggesting that accurate staging of the regional lymph node bed is possible in patients after WLE.     

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

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

Applicability of the Sentinel Node Technique to Merkel Cell Carcinoma

BACKGROUND: Merkel cell carcinoma (MCC) resembles malignant melanoma in several ways. Both are cutaneous lesions of the same embryonic origin. Both have an unpredictable biologic behavior, early regional lymph node involvement, early distant metastases, and high recurrence rate. OBJECTIVE: To apply the sentinel node technique described for melanoma to MCC in light of the common biologic features of these two tumors. METHODS: Preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and sentinel node biopsy and frozen section histology were performed to guide the surgical treatment of three patients with MCC. RESULTS: Application of this approach in patients with MCC is feasible, reproducible, and seems reliable. CONCLUSION: The use of the sentinel node technique for MCC will reduce the number of unnecessary lymphadenectomies, will enable identification of microscopic metastases to lymph nodes, and will improve the stratification and accrual of patients into adjuvant treatment protocols. It may even lead to a survival benefit.     

Fluorescence-guided lymph node sampling is feasible during up-front or delayed nephrectomy for Wilms tumor

BackgroundLymph node sampling is critical to surgical staging in Wilms tumor; failure to sample lymph nodes is associated with under-staging and an increased incidence of local relapse. However, no standard lymphatic mapping method is currently being utilized for Wilms tumor to aid identification of regional draining lymph nodes. Herein, we describe the use of fluorescence-guided lymphatic mapping for Wilms tumor.Materials and methodsTwo tertiary level referral centers independently began indocyanine green (ICG) fluorescence-guided nodal mapping. In one center, this was achieved with ipsilateral intra-parenchymal (IP) injection of ICG during minimally invasive tumor nephrectomy (MIN) following neoadjuvant chemotherapy and in the other, with Peri?Hilar (PH) injection during upfront, open tumor nephrectomy (ON). Successful lymph node mapping was defined as the presence of fluorescence signal in draining lymph nodes.ResultsEight patients (median age of 2.5 years) underwent fluorescence-guided lymphatic mapping (four IP and four PH injection). Lymphatic mapping was successful in seven patients (88%) including each of the four patients with IP injection.ConclusionsFluorescence-guided lymphatic mapping of Wilms tumor drainage is feasible by both IP injection and PH injection techniques. However, whether lymphatic mapping improves the precision of lymph node sampling is unknown and should be studied in prospective trials.     

Preliminary Outcome Analysis in Patients With Breast Cancer and a Positive Sentinel Lymph Node Who Declined Axillary Dissection

Background:This retrospective study was designed to provide a preliminary outcome analysis in patients with positive sentinel nodes who declined axillary dissection.Methods:A review was conducted of patients who underwent lumpectomy and sentinel lymph node excision for invasive disease between January 1998 and July 2000. Those who were found to have sentinel lymph node metastasis without completion axillary dissection were selected for evaluation. Follow-up included physical examination and mammography.Results:Thirty-one patients were identified who met inclusion criteria. Primary invasive cell types included infiltrating ductal carcinoma, infiltrating lobular carcinoma, and mixed cellularity. Most primary tumors were T1. Nodal metastases were identified by hematoxylin and eosin stain and immunohistochemistry. Twenty-seven of the metastases were microscopic (<2 mm), and the remaining four were macroscopic. All patients received adjuvant systemic therapy. With a mean follow-up of 30 months, there have been no patients with axillary recurrence on physical examination or mammographic evaluation.Conclusions:We have presented patients with sentinel lymph nodes involved by cancer who did not undergo further axillary resection and remain free of disease at least 1 year later. This preliminary analysis supports the inclusion of patients with subclinical axillary disease in trials that randomize to observation alone.     

Detection of occult metastasis in squamous cell carcinoma of the penis using a dynamic sentinel node procedure

PURPOSE: We evaluated the so-called dynamic sentinel node procedure in patients with penile cancer. This new staging technique consists of excisional biopsy of the first lymph node onto which a tumor drains the so-called sentinel node, based on individual mapping of lymphatic drainage. MATERIALS AND METHODS: From 1994 to 1998, 55 consecutive patients with stage T2 or greater bilateral or unilateral node negative squamous cell carcinoma of the penis were prospectively entered in this study. Tumor stage was T2N0 in 42, T2N1 in 4 and T3N0 in 9 cases. To locate the sentinel node each patient underwent lymphoscintigraphy with 99mtechnetium nanocolloid injected intradermally around the tumor. The following day the sentinel node was identified intraoperatively using patent blue dye injected intradermally around the tumor and a gamma detection probe. Regional lymph node dissection was restricted to patients with a tumor positive sentinel node only. RESULTS: Scintigraphy revealed 125 sentinel nodes in 107 inguinal regions, including no sentinel node in 2 patients, 1 or more unilateral nodes in 10 and bilateral drainage in 43. At surgery 108 sentinel nodes were removed. In 8 patients with 2 or more sentinel nodes on lymphoscintigraphy only 1 was noted intraoperatively and in 9 an additional sentinel node was removed, which was not identified by scintigraphy. All nodes were identified with the gamma detection probe. In 1 patient a wound abscess developed. Regional lymph node dissection was performed in 11 patients with sentinel node metastasis. Median followup was 22 months (range 4.1 to 61). In 1 patient lymph node metastasis was noted at followup despite prior excision of a tumor-free sentinel node. CONCLUSIONS: The dynamic sentinel node procedure is a promising staging technique to detect early metastatic dissemination of penile cancer based on individual mapping of lymphatic drainage, and enables identification of patients with clinically node negative disease requiring regional lymph node dissection.     

Outcome of patients with melanoma and histologically negative sentinel lymph nodes

HYPOTHESIS: Patients with melanoma and histologically negative sentinel lymph nodes identified by lymphatic mapping have a very good prognosis. DESIGN: Cohort study with follow-up information obtained from medical records and telephone interviews. SETTING AND PATIENTS: Of all patients with cutaneous melanoma who underwent intraoperative sentinel lymph node mapping between November 15, 1993, and April 18, 1997, at the Massachusetts General Hospital, Boston, 89 were found to have no evidence of melanoma in their sentinel nodes. Forty-six lesions (51%) were on an extremity and 44 (49%) were of axial location. The median tumor thickness was 1.8 mm (range, 0.36-12.0 mm) and 11 tumors (12%) were ulcerated. INTERVENTIONS: Patients underwent intraoperative sentinel lymph node mapping with lymphazurin and radiolabeled sulfur colloid. Sentinel lymph nodes were analyzed by standard hematoxylin-eosin staining. Only 2 patients received adjuvant therapy following wide excision of the primary lesion. MAIN OUTCOME MEASURES: Site of initial recurrence and time to initial recurrence. RESULTS: The median follow-up for all patients was 23 months (range, 2-54 months). Eleven patients (12%) developed melanoma recurrences, and 78 (88%) patients remain disease free. Regional lymph nodes were the initial site of recurrence in 7 (8%) of 89 patients, and 7 (7%) of 106 mapped basins. Four patients had recurrence without involvement of regional lymph nodes: 2 with distant metastases and 2 with in transit metastases. The median time to recurrence was 12 months (range, 2-35 months). Sentinel lymph nodes were reanalyzed using serial sections and immunoperoxidase stains in 7 patients with recurrence and metastatic melanoma was identified in 3 (43%). CONCLUSIONS: The risk for melanoma recurrence is relatively low in patients with histologically negative sentinel nodes identified by lymphatic mapping. Longer follow-up will improve our understanding of the prognostic value of this procedure.     

Role of Sentinel Lymph Node Biopsy in Patients With Thin (<1 mm) Primary Melanoma

Background: Thin melanomas have become increasingly prevalent, and lesions 1 mm in thickness are frequently diagnosed. They are considered highly curable when treated solely with wide local excision, with reported 5-year disease-free survivals of 95% to 98%. However, thin Clark level III and IV melanomas may have increased potentials for metastasizing and late recurrences because of dermal lymphatics located at the interface of the papillary and reticular dermis. We have addressed this controversial area by reviewing the outcomes of patients with invasive thin melanomas.Methods: We performed 266 sentinel lymph node biopsy procedures, using both radioisotope and blue dye, over a 5-year period. Sixty-five of the 266 invasive melanomas were thin and were treated by wide local excision and sentinel lymph node biopsy.Results: Two (3%) of the 65 thin melanomas were found to have a positive sentinel lymph node. In melanomas thinner than .75 mm, no positive sentinel lymph node was found. Therefore, only 3% of patients may benefit from tumor upstaging by sentinel lymph node biopsy.Conclusions: The occurrence of regional lymph node metastases in thin melanomas is rather low. Our data suggest that sentinel lymph node biopsy may not justified in patients with melanoma <.75 mm thick.     

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

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

Metastasis of primary melanoma to two separate lymph node basins: Prognostic significance

Background and Methods: Depending on the location of the primary lesion, melanoma patients may develop metastases in more than one regional lymph node basin. To determine whether this is prognostically significant, we reviewed our experience with melanoma patients who had undergone regional lymphadenectomy (RLND) in two separate basins. Results: Of 3,603 patients who underwent RLND between April 1971 and January 1993, 406 underwent procedures in two separate basins; of these, 120 (30%) had metastases in both basins and 124 (30%) had metastases in one basin. When calculated from the first positive RLND, 1-year, 3-year, and 5-year survival rates were 82%, 48%, and 33%, respectively, for patients with dual-basin involvement and 88%, 59%, and 48%, respectively, for patients with single-basin involvement (p=0.0173). Median survival from the first positive RLND was 33.5 months for dual-basin involvement and 56.6 months for single-basin involvement. Univariate analysis demonstrated that Breslow thickness of the primary melanoma, clinical status of the regional lymph nodes, number of positive RLNDs, and tumor burden (total number of positive lymph nodes) were significant indicators of survival. The patient's age and gender, the anatomic location and Clark level of the primary melanoma, the disease-free interval before regional metastasis, and the site and timing of RLNDs were not significant by univariate analysis. Multivariate analysis demonstrated significance for Breslow thickness, number of positive RLNDs, and tumor burden. Conclusions: The survival rate of melanoma patients with regional metastases in two lymph node basins is lower than that of patients with an equal tumor burden confined to a single basin. This suggests that primary melanomas metastasizing to more than one lymph node basin may have a higher metastatic potential, or that dual-basin involvement may increase the risk of systemic spread. We advocate lymphatic mapping, sentinel node biopsy, and selective lymphadenectomy as a cost-effective technique with little morbidity to identify and manage occult metastases in patients who have two lymph basins at risk. Presented at the 47th Annual Cancer Symposium of The Society of Surgical Oncology, Houston, Texas, March 17–20, 1994.     

Aberrant sentinel nodes in malignant melanoma.

The option of sentinel lymph node biopsy for patients with a cutaneous malignant melanoma has allowed an alternative to the traditional approaches to lymph node basin surgery. Lymphatic mapping usually identifies the sentinel node(s) in a recognised lymphatic basin, however aberrant nodes may occasionally be identified outside these areas. The notes of 100 consecutive patients with a localised cutaneous malignant melanoma, who had a sentinel lymph node biopsy in our unit, were reviewed. Lymphatic mapping identified three patients with aberrant sentinel lymph nodes. Failure to remove an aberrant sentinel lymph node harbouring metastatic melanoma may reduce significantly the chance of control or cure of the disease. In order to reduce this risk we advocate lymphatic mapping prior to surgical management of the draining lymph nodes of a cutaneous malignant melanoma.     

Merkel cell carcinoma in pelvic lymph nodes after surgical staging for endometrial cancer: A case report and review of the literature

INTRODUCTIONMerkel cell carcinoma (MCC) is a rare malignant neuroendocrine tumor of the skin.PRESENTATION OF CASEWe present a case of MCC in pelvic lymph nodes, revealed after surgical staging for endometrial cancer. A 54-year-old Caucasian woman presented to our department with a three-month history of postmenopausal bleeding. After proper preoperative evaluation, the patient underwent total abdominal hysterectomy, bilateral salpingo-ophorectomy and pelvic lymph node dissection. The pathology report confirmed the presence of a small, grade I, endometrioid adenocarcinoma and MCC in the pelvic lymph nodes. Primary site of the disease could not been retrieved. The tumor board decided adjuvant chemotherapy (carboplatin and etoposide) and close follow-up every 2 months. Our patient is alive with no evidence of disease 12 months after surgery.DISCUSSIONIt is noteworthy that 19% of the patients with MCC had lymph node metastasis with no apparent primary lesion. The mechanism of this regression remains unclear, although a higher apoptotic activity has been observed in MCC than other skin tumors. In addition, other co-malignancies have also been linked to MCC patients. The explanation for the frequent occurrence of other primary neoplasms in patients with MCC is still unclear. However, a reasonable cause could be an altered genetic profile or an immuno-compromised situation in these patients.CONCLUSIONFurther analytic investigations are needed to clarify the role of various factors in the spontaneous regression or not of this neuroendocrine tumor as well as in the simultaneous genesis of other primary carcinomas.     

Sentinel Lymph Node Biopsy for Melanoma: How Many Radioactive Nodes Should be Removed?

Background: Sentinel lymph node (SLN) biopsy has become a standard method of staging patients with cutaneous melanoma. Sentinel lymph node biopsy usually is performed by intradermal injection of a vital blue dye (isosulfan blue) plus radioactive colloid (technetium sulfur colloid) around the site of the tumor. Intraoperative gamma probe detection has been shown to improve the rate of SLN identification compared to the use of blue dye alone. However, multiple sentinel nodes often are detected using the gamma probe. It is not clear whether these additional lymph nodes represent true sentinel nodes, or second-echelon lymph nodes that have received radiocolloid particles that have passed through the true sentinel node. This analysis was performed to determine the frequency with which these less radioactive lymph nodes contain metastatic disease when the most radioactive, or hottest, node does not.Materials and Methods: In the Sunbelt Melanoma Trial, 1184 patients with cutaneous melanoma of Breslow thickness 1.0 mm or more had sentinel lymph nodes identified. Sentinel lymph node biopsy was performed by injection of technetium sulfur colloid plus isosulfan blue dye in 99% of cases. Intraoperative determination of the degree of radioactivity of sentinel nodes (ex vivo) was measured, as well as the degree of blue dye staining.Results:Sentinel nodes were identified in 1373 nodal basins in 1184 patients. A total of 288 of 1184 patients (24.3%) were found to have sentinel node metastases detected by histology or immunohistochemistry. Nodal metastases were detected in 306 nodal basins in these 288 patients. There were 175 nodal basins from 170 patients in which at least one positive sentinel node was found and more than one sentinel node was harvested. Blue dye staining was found in 86.3% of the histologically positive sentinel nodes and 66.4% of the negative sentinel nodes. In 40 of 306 positive nodal basins (13.1%), the most radioactive sentinel node was negative for tumor when another, less radioactive, sentinel node was positive for tumor. In 20 of 40 cases inding a positive sentinel node other than the hottest node.Conclusions: If only the most radioactive sentinel node in each basin had been removed, 13.1% of the nodal basins with positive sentinel nodes would have been missed. It is recommended that all blue lymph nodes and all nodes that measure 10% or higher of the ex vivo radioactive count of the hottest sentinel node should be harvested for optimal detection of nodal metastases.Preliminary findings presented at the annual meeting of the Society of Surgical Oncology, Orlando, Florida, March 4–7, 1999.     

Delayed Harvesting of Sentinel Lymph Nodes After Previous Wide Local Excision of Extremity Melanoma

Background:Harvesting the sentinel lymph node (SLN) is important in the management of patients with primary cutaneous melanoma. Selective sentinel lymphadenectomy (SSL) is generally performed at the time of wide local excision (WLE). The aim of our study was to determine whether delayed SSL is useful in detecting micrometastasis to the regional basin in patients with previous WLE of an extremity melanoma.Methods:Of 203 patients with a primary melanoma site located on the upper or lower extremity seen at the University of California, San Francisco/Mount Zion Melanoma Center from May 17, 1994, to March 23, 1999, 24 patients had a WLE of their extremity melanoma with adequate margins before referral. SSL was performed to assess micrometastasis in the regional lymph node basin after preoperative lymphoscintigraphy.Results:At least 1 SLN was identified in all 24 patients. At a median follow-up of 3 years, two patients showed micrometastasis in the SLNs. One of these two patients developed recurrence, and all remaining patients showed no evidence of disease.Conclusions:Although it is generally advised that WLE should be performed simultaneously with SSL, delayed SSL after WLE of an extremity melanoma can still provide valuable staging information, which is critical for management of the patient.     

Single Intralesional Tracer Dose for Radio-Guided Excision of Clinically Occult Breast Cancer and Sentinel Node

Background: The purpose of this study was to determine the feasibility of both lymphatic mapping and probe-guided primary tumor excision by use of intralesional tracer administration in clinically occult breast cancer.Methods: Sixty patients with a clinically occult breast lesion were prospectively included. Lymphoscintigraphy was performed after intratumoral injection of ^99mTc-labeled nanocolloid guided by ultrasound or stereotaxis. A catheter over a localization wire was inserted for intraoperative blue dye administration by using the same imaging techniques. After sentinel node identification, the gamma-ray detection probe was used for radio-guided wide local excision in patients who underwent breast-conserving therapy.Results: A sentinel node was visualized on the scintigrams in 56 patients 93% and could be identified intraoperatively in 58 patients 97%. A sentinel node contained tumor in 10 17% of these patients. Extra-axillary sentinel nodes were visualized in 43%, were collected in 38%, and contained metastasis in 7% of the patients. Complete excision of the primary tumor could be accomplished in 39 87% of 45 patients.Conclusions: Both sentinel node biopsy and probe-guided excision of a nonpalpable breast cancer is feasible with the aid of intralesional tracer administration. Sentinel node metastasis was found in 17% of the patients. A remarkably high percentage of extra-axillary drainage 43% was observed.     

A Meta-analysis of the Prognostic Significance of Sentinel Lymph Node Status in Merkel Cell Carcinoma

BACKGROUND: Merkel cell carcinoma is an aggressive cutaneous neoplasm with a high propensity to metastasize to lymph nodes. OBJECTIVE: The objective of this study was to determine the prognostic significance of sentinel lymph node status in patients with Merkel cell carcinoma. METHODS: A meta-analysis of case series of patients with Merkel cell carcinoma managed with sentinel lymph node biopsy was performed. RESULTS: Forty of 60 patients (67%) had a biopsy-negative sentinel lymph node; 97% of this group had no recurrence at 7.3 months median follow-up. Twenty patients (33%) had a biopsy-positive sentinel lymph node; 33% of this group experienced local, regional, or systemic recurrence at 12 months median follow-up. Risk of recurrence or metastasis was 19-fold greater in biopsy-positive patients (odds ratio, 18.9; p = 0.005). None of 15 biopsy-positive patients who underwent therapeutic lymph node dissection experienced a regional recurrence; 3 of 4 who did not receive therapeutic lymphadenectomy experienced regional recurrence. CONCLUSION: Sentinel lymph node positivity is strongly predictive of a high short-term risk of recurrence or metastasis in patients with Merkel cell carcinoma. Therapeutic lymph node dissection appears effective in preventing short-term regional nodal recurrence. Aggressive adjuvant treatment should be considered for patients with positive sentinel lymph nodes.