Validation of the Back-table Graft Arterial Anastomosis between the Splenic Artery and Superior Mesenteric Artery: Arterial Complications after a 21-year Single-center Experience of Pancreas Transplantation.

OBJECTIVE: To determine the role of the arterial splenomesenteric anastomosis (ASMA) vascular reconstruction technique in terms of arterial vascular complications in pancreas transplant (PT) recipients. SUMMARY BACKGROUND DATA: The ASMA technique was first described in 1992 by Hospital Clínic Barcelona group. Regardless that the iliac Y-graft technique is the most frequently used worldwide, evidence of arterial complications and implications of using a different back-table reconstruction is conspicuously absent in the literature. METHODS: Descriptive review of 407 PTs performed at a single center (1999-2019) by analyzing the type of arterial reconstruction technique, focusing on ASMA. The endpoints were the management of arterial complications and long-term patient and graft survival. RESULTS: ASMA was performed in 376 cases (92.4%) and a Y-graft in 31 cases (7.6%). A total of 34 arterial complications (8.3%) were diagnosed. In the ASMA group (n=30, 7.9%) they comprised: 15 acute thrombosis; 4 stenosis; 1 pseudoaneurysm and 10 diverse chronic arterial complications while in the Y-graft group (n=4, 12.9%) 3 acute thrombosis and 1 chronic artery-duodenal fistula occurred. Graft salvage was achieved in 16 patients (53.3%) from the ASMA group and in 2 (50%) from the Y-graft. After a median follow-up of 129.2 (IQR 25-75%, 77.2 -182) months the overall graft and patient survival for the whole cohort at 1, 5, and 10 years was 86.7%, 79.5%, 70.5%, and 98.5%, 95.3%, 92.5%, respectively. CONCLUSIONS: The ASMA proves to be a safe and more easily reproducible technique and should therefore be considered for first-line back-table reconstruction in the PT population.

Unilateral axilo-breast approach (UABA) with gas insufflation versus open conventional hemithyroidectomy: A prospective comparative study.

BACKGROUND: The objective of this study was to compare with the conventional open approach, the surgical and aesthetic results of endoscopic thyroidectomy via unilateral axillo-breast approach (UABA) with gas insufflation in patients with a unilateral thyroid nodule. METHODS: Between August 2017 and August 2020, a prospective comparative cohort study was carried out in patients proposed for hemithyroidectomy. The patients were assigned to one type of approach (Open or Endoscopic) in a successive manner. Surgical results and aesthetic satisfaction at hospital discharge and during the 12-month follow-up were evaluated and compared between both groups. RESULTS: A total of 200 patients were included in the study: 100 for the Open approach and 100 for the Endoscopic. The baseline patient characteristics were similar between both groups. Total operative time was longer in the Endoscopic approach, due to the time required for subcutaneous dissection (the hemithyroidectomy time was similar in both groups). There was no significant difference in the frequency of major complications. The length of hospital stay was longer (for 1 day) in the Endoscopic group. The aesthetic satisfaction of the patients was significantly higher in the Endoscopic than in the Open group (p < 0.001), at hospital discharge and at 12-month follow-up. CONCLUSION: UABA with gas insufflation for hemithyroidectomy represents a safe and effective therapeutic option for the treatment of unilateral benign thyroid pathologies.

Intraoperative electron radiation therapy after salvage surgery in gynecological cancers and retroperitoneal sarcomas: outcomes and adverse effects.

Background: Salvage surgery is considered an option for isolated recurrences of retroperitoneal and pelvic tumors, in patients who have undergone previous radiotherapy. In order to increase local control intra operative electron radiation therapy (IOERT) can be used in these patients to administer additional radiation dose. We evaluated the outcomes and adverse effects in patients with retroperitoneal sarcoma and gynecologic tumors after salvage surgery and IOERT. Materials and methods: Twenty patients were retrospectively analyzed. Twenty-three IOERT treatments were performed after surgery. Six (30%) were sarcoma and 14 (70%) were gynecological carcinoma. Administered dose depended on previous dose received with external beam radiotherapy (EBRT) and proximity to critical structures. The toxicities were scored using the Common Terminology Criteria for Adverse Events version 4.0. Results: The median age of the patients was 51 years (range 34-70). After a median follow-up of 32 months (range 1-68), in the sarcoma group the local control rate was 66.6%; while in the gynecological group the local control rate was 64.3%. In relation to late toxicity, one patient had a Grade 2 vesicovaginal fistula, and one patient presented Grade 4 enterocolitis and enteric intestinal fistula. Conclusions: IOERT could have a role in the treatment of retroperitoneal sarcomas in primary tumors after EBRT, as it may suggest a benefit in local control or recurrences after surgical resection in those at high risk of microscopic residual disease. The addition of IOERT to salvage resection for isolated recurrence of gynecologic cancers suggest favorable local control in cases with concern for residual microscopic disease.

Thyroidectomy via unilateral axillo-breast approach (UABA) with gas insufflation: prospective multicentre European study.

BACKGROUND: Extracervical approaches for thyroidectomy are seldom explored in the western population. The objective of this study was to evaluate the outcomes of hemithyroidectomy via endoscopic unilateral axillo-breast approach (UABA) with gas insufflation. METHOD: Consecutive patients undergoing UABA hemithyroidectomy for symptomatic benign or cytologically indeterminate nodules (Bethesda III lesions) of less than 5 cm from July 2015 to December 2020 at three European institutions were included. Patients were excluded if presenting with a BMI more than 25 kg/m2, had previous neck surgery and/or radiation, had bilateral thyroid lesions, retrosternal goitre, Hashimoto thyroiditis or Graves' disease. Follow-up was carried out at 2 weeks, 3 months and 1 year. Outcomes of interest were surgical (including operating time, mean duration of hospital stay and complications) and self-assessed cosmetic outcomes. RESULTS: Out of 984 patients treated with hemithyroidectomy during the study interval, 253 were selected, including 214 women and 39 men. Patients' mean age was of 46.6 years with a mean BMI of 22.57. Mean operating time was 72.9 minutes. A transient recurrent laryngeal nerve injury was reported in 3.6 per cent of the patients, but none was persistent. Transient pectoral/cervical hypoesthesia was noted in 24.1 per cent of patients, with no permanent hypoesthesia. Skin burns and subcutaneous hematoma developed in 2.4 per cent and 2 per cent of patients but resolved within the third month after surgery. There was no tracheal/oesophageal perforation, conversion to open surgery or reoperation. The final pathology revealed 241 benign nodules, nine underlying papillary thyroid carcinomas, and three cases of follicular carcinoma. Hospital discharge was achieved on the first in 68.8 per cent of the patients and on the second postoperative day in 31.2 per cent of the cases. All patients were satisfied with the cosmetic aspect. CONCLUSION: In selected patients, UABA with gas insufflation for hemithyroidectomy could be performed for the treatment of unilateral thyroid pathologies.

Sentinel Lymph Node Biopsy vs. Observation in Thin Melanoma: A Multicenter Propensity Score Matching Study.

The therapeutic value of sentinel lymph node biopsy (SLNB) in thin melanoma remains controversial. The aim of this study is to determine the role of SLNB in the survival of thin melanomas (≤1 mm). A multicenter retrospective observational study was designed. A propensity score matching was performed to compare patients who underwent SLNB vs. observation. A multivariate Cox regression was used. A total of 1438 patients were matched by propensity score. There were no significant differences in melanoma-specific survival (MSS) between the SLNB and observation groups. Predictors of MSS in the multivariate model were age, tumor thickness, ulceration, and interferon treatment. Results were similar for disease-free survival and overall survival. The 5- and 10-year MSS rates for SLN-negative and -positive patients were 98.5% vs. 77.3% (p < 0.001) and 97.3% vs. 68.7% (p < 0.001), respectively. SLNB does not improve MSS in patients with thin melanoma. It also had no impact on DSF or OS. However, a considerable difference in MSS, DFS, and OS between SLN-positive and -negative patients exists, confirming its value as a prognostic procedure and therefore we recommend discussing the option of SLNB with patients.

Survival analysis and sentinel lymph node status in thin cutaneous melanoma: A multicenter observational study.

Mitotic rate is no longer considered a staging criterion for thin melanoma in the 8th edition of the American Joint Committee on Cancer Staging Manual. The aim of this observational study was to identify prognostic factors for thin melanoma and predictors and prognostic significance of sentinel lymph node (SLN) involvement in a large multicenter cohort of patients with melanoma from nine tertiary care hospitals. A total of 4249 consecutive patients with thin melanoma diagnosed from January 1, 1998 to December 31, 2016 were included. The main outcomes were disease-free interval and melanoma-specific survival for the overall population and predictors of SLN metastasis (n = 1083). Associations between survival and SLN status and different clinical and pathologic variables (sex, age, tumor location, mitosis, ulceration, regression, lymphovascular invasion, histologic subtype, Clark level, and Breslow thickness) were analyzed by Cox proportional hazards regression and logistic regression. SLN status was the most important prognostic factor for melanoma-specific survival (hazard ratio, 13.8; 95% CI, 6.1-31.2; P < 0.001), followed by sex, ulceration, and Clark level for patients who underwent SLNB. A mitotic rate of >2 mitoses/mm2 was the only factor associated with a positive SLN biopsy (odds ratio, 2.9; 95% CI, 1.22-7; P = 0.01. SLN status is the most important prognostic factor in thin melanoma. A high mitotic rate is associated with metastatic SLN involvement. SLN biopsy should be discussed and recommended in patients with thin melanoma and a high mitotic rate.

Sentinel lymph node biopsy versus observation in thick melanoma: A multicenter propensity score matching study.

The clinical value of sentinel lymph node (SLN) biopsy in thick melanoma patients (Breslow >4 mm) has not been sufficiently studied. The aim of the study is to evaluate whether SLN biopsy increases survival in patients with thick cutaneous melanoma, and, as a secondary objective, to investigate correlations between survival and lymph node status. We included 1,211 consecutive patients with thick melanomas (>4 mm) registered in the participating hospitals' melanoma databases between 1997 and 2015. Median follow-up was 40 months. Of these patients, 752 were matched into pairs by propensity scores based on sex, age, tumor location, histologic features of melanoma, year of diagnosis, hospital and adjuvant interferon therapy. The SLN biopsy vs. observation was associated with better DFS [adjusted hazard ratio (AHR), 0.74; 95% confidence interval (CI) 0.61-0.90); p = 0.002] and OS (AHR, 0.75; 95% CI, 0.60-0.94; p = 0.013) but not MSS (AHR, 0.84; 95% CI, 0.65-1.08; p = 0.165). SLN-negative patients had better 5- and 10-year MSS compared with SLN-positive patients (65.4 vs. 51.9% and 48.3 vs. 38.8%; p = 0.01, respectively). As a conclusion, SLN biopsy was associated with better DFS but not MSS in thick melanoma patients after adjustment for classic prognostic factors. SLN biopsy is useful for stratifying these patients into different prognostic groups.

Prognostic role of the histological subtype of melanoma on the hands and feet in Caucasians.

Acral melanoma (AM) is associated with a poor prognosis in part because of delayed diagnosis, but probably also because of other intrinsic characteristics of location. The aim of this study was to review the specific characteristics and outcome of AM in Caucasians. This was a cross-sectional retrospective clinical-pathological study of 274 patients identified with AM in the database of a referral unit in Europe from 1986 to 2010. The mean age of the patients was 56.6 (SD 17.7) years. 269 cases could be histologically classified and included in the study. In all, 222 (82.5%) were located on feet. According to melanoma subtype, 165 (61.3%) were acral lentiginous melanoma (ALM), 84 (31.2%) were superficial spreading melanoma (SSM), and 20 (7.5%) were nodular melanoma (NM). SSM patients were characterized by female predominance (77.4%), younger age, and classic melanoma-risk phenotype (fair skin and multiple nevi). Among the 198 invasive cases with a mean follow-up of 56.2 months, the mean (SD) Breslow's thickness was 3.1 (3.6) mm, being 1.4 (1.4) mm in SSM, 3.5 (4.1) mm in ALM and 4.9 (2.9) mm in NM (P<0.001). Ulceration was present in 33.3%, 2.9% in SSM, 38.6% in ALM, and 76.9% in NM (P<0.001). A total of 29.3% relapsed (7.3% of SSM, 35% of ALM and 55% of NM) and 24.2% died because of AM. In multivariate analysis, age at diagnosis, Breslow, and histopathological subtype were independent prognostic factors for both disease-free and AM-specific survival. The ALM and NM subtypes presented poorer outcome after weighting Breslow and age (P=0.02). Histological subtype of AM could have an impact on biological behavior, ALM and NM subtypes presenting a poorer prognosis after adjusting for age and Breslow's thickness.

Performance of diagnostic tests in an intensive follow-up protocol for patients with American Joint Committee on Cancer (AJCC) stage IIB, IIC, and III localized primary melanoma: A prospective cohort study.

BACKGROUND: There is no international consensus on optimal follow-up schedules and which supplementary tests should be used after resection of a primary melanoma. OBJECTIVE: We sought to analyze the performance of the follow-up components and identify procedures that detect melanoma metastasis earlier. METHODS: This was a prospective cohort from 290 consecutive patients given a diagnosis of stage IIB, IIC, and III melanoma. Patients were followed up with an intensive protocol based on imaging studies (computed tomography of the chest, abdomen, and pelvis, and brain magnetic resonance imaging), periodic laboratory tests, regular physical examinations, and patient self-examinations. RESULTS: A total of 2382 clinical examinations and 3069 imaging tests were performed. The patients completed 899.8 person-years of follow-up, with a median of 2.5 years. In all, 115 recurrences in 290 patients were recorded, of which computed tomography detected 48.3%; brain magnetic resonance imaging, 7.6%; laboratory test, 2.5%; physician, 23.7%; and patient, 17.8%. LIMITATIONS: Patients with stage III melanoma were not systematically classified into subgroups and overall survival was not evaluated. CONCLUSION: We observed that this intensive monitoring is appropriate for early detection of recurrence in stage IIB, IIC, and III melanoma. Prompt diagnosis of metastasis and the recent development of new therapeutic targets may improve overall survival.

Effect of time to sentinel-node biopsy on the prognosis of cutaneous melanoma.

INTRODUCTION: In patients with primary cutaneous melanoma, there is generally a delay between excisional biopsy of the primary tumour and sentinel-node biopsy. The objective of this study is to analyse the prognostic implications of this delay. PATIENTS AND METHOD: This was an observational, retrospective, cohort study in four tertiary referral hospitals. A total of 1963 patients were included. The factor of interest was the interval between the date of the excisional biopsy of the primary melanoma and the date of the sentinel-node biopsy (delay time) in the prognosis. The primary outcome was melanoma-specific survival and disease-free survival. RESULTS: A delay time of 40 days or less (hazard ratio (HR), 1.7; confidence interval (CI), 1.2-2.5) increased Breslow thickness (Breslow ⩾ 2 mm, HR, > 3.7; CI, 1.4-10.7), ulceration (HR, 1.6; CI, 1.1-2.3), sentinel-node metastasis (HR, 2.9; CI, 1.9-4.2), and primary melanoma localised in the head or neck were independently associated with worse melanoma-specific survival (all P < 0.03). The stratified analysis showed that the effect of delay time was at the expense of the patients with a negative sentinel-node biopsy and without regression. CONCLUSION: Early sentinel-node biopsy is associated with worse survival in patients with cutaneous melanoma.

High nevus counts confer a favorable prognosis in melanoma patients.

A high number of nevi is the most significant phenotypic risk factor for melanoma and is in part genetically determined. The number of nevi decreases from middle age onward but this senescence can be delayed in patients with melanoma. We investigated the effects of nevus number count on sentinel node status and melanoma survival in a large cohort of melanoma cases. Out of 2,184 melanoma cases, 684 (31.3%) had a high nevus count (>50). High nevus counts were associated with favorable prognostic factors such as lower Breslow thickness, less ulceration and lower mitotic rate, despite adjustment for age. Nevus count was not predictive of sentinel node status. The crude 5- and 10-year melanoma-specific survival rate was higher in melanomas cases with a high nevus count compared to those with a low nevus count (91.2 vs. 86.4% and 87.2 vs. 79%, respectively). The difference in survival remained significant after adjusting for all known melanoma prognostic factors (hazard ratio [HR] = 0.43, confidence interval [CI] = 0.21-0.89). The favorable prognostic value of a high nevus count was also seen within the positive sentinel node subgroup of patients (HR = 0.22, CI = 0.08-0.60). High nevus count is associated with a better melanoma survival, even in the subgroup of patients with positive sentinel lymph node. This suggests a different biological behavior of melanoma tumors in patients with an excess of nevi.

Added value of intraoperative real-time imaging in searches for difficult-to-locate sentinel nodes.

UNLABELLED: Localization of sentinel lymph nodes can be challenging if they are in difficult anatomic locations or near high radiotracer activity. The purpose of this study was to assess the value of intraoperative real-time imaging using a portable gamma-camera in conjunction with a conventional gamma-counting probe when it is difficult to localize the sentinel node. METHODS: After (99m)Tc-nanocolloid injection, patients with various malignancies underwent presurgical lymphoscintigraphy followed by surgery (usually the next day). We evaluated 20 patients who required sentinel lymph node biopsy and in whom the location or other characteristics of the sentinel node would make intraoperative retrieval difficult. During surgery, the sentinel node was localized using a portable gamma-camera together with a hand-held gamma-probe. A (153)Gd pointer or (125)I seed was used to better depict the sentinel node location in real time. RESULTS: Using only a conventional hand-held gamma-probe, surgeons were able to definitively localize the sentinel node in 15 of 20 patients. Intraoperatively, the portable gamma-camera showed uptake by the definite sentinel node in 19 of 20 patients and helped to precisely localize the node with the hand-held gamma-probe in 4 patients. In 1 of these patients, the sentinel node was metastatic. CONCLUSION: The combination of a standard hand-held gamma-probe and real-time imaging provided by a portable gamma-camera offers a high intraoperative detection rate in patients with difficult sentinel node localization as assessed by presurgical lymphoscintigraphy.

Small cell melanoma and ulceration as predictors of positive sentinel lymph node in malignant melanoma patients.

Malignant melanoma (MM) early lymph node (LN) metastasis usually appears first in the sentinel LN (SLN). Breslow thickness is the main factor considered in the selection of patients to be submitted to SLN biopsy. The present study aimed to describe other independent prognostic factors useful in SLN candidate selection. During one year, 94 MM patients (90 primary cutaneous MM with Breslow thickness > or = 0.76 mm, and four cutaneous relapses), were submitted to SLN biopsy in the Melanoma Unit at the Hospital Clinic, Barcelona, Spain. The prognostic factors studied were: Breslow thickness, Clark's level of invasion, mitotic rate, cellular type (small, epithelioid, fusocellular, sarcomatoid), vertical growth phase, regression > 50%, severe vascularization, infiltrate (lymphocytic, plasmocytic), ulceration, neurotropism, intravascular/intraneural invasion, protein p16 expression and recurrence. Nineteen SLN (20.2%) were positive and 75 (79.8%) negative. No positive SLN occurred in MM with Breslow thickness < or = 1.0 mm. Breslow thickness > or = 2 mm (P = 0.005), severe vascularization (P = 0.005), small cell (P = 0.000) and ulceration (P = 0.005) were significant prognostic factors by univariate analysis. Small cell (P = 0.008) and ulceration (P = 0.05) were also significant prognostic factors in a multivariate analysis. The probability of finding a positive SLN for small cell was 56.9% [95% confidence interval (CI), 26.8-82.6%]. The probability of positive SLN for ulceration was 35.5% (95% CI, 14.2-64.7%). For small cell and ulceration together the probability increased to 86.3% (95% CI, 54.3-97.1%). The results of this study corroborated ulceration as a prognostic factor for SLN candidate selection and for the first time we have described small cell melanoma morphology as a significant factor associated with positive SLN.

Is the identification of in-transit sentinel lymph nodes in malignant melanoma patients really necessary?

The sentinel lymph node (SLN) is the first node in a nodal basin to receive the direct lymphatic flow from a malignant melanoma. However, in some patients, lymphoscintigraphic study reveals the presence of lymphatic nodes in the area between the primary melanoma and the regional basin. These nodes are called "in-transit nodes" or "interval nodes" and, by definition, are also SLNs. The purpose of this study was to determine the incidence and location of in-transit SLNs in patients with malignant melanoma and to assess whether it is really necessary to harvest them. The evaluation involved 600 consecutive malignant melanoma patients. Lymphoscintigraphy was performed on the day before surgery following intradermal injection of 74-111 MBq of (99m)Tc-nanocolloid in four doses around the primary melanoma or the biopsy scar. Dynamic and static images were obtained and revealed SLNs in 599 out of 600 patients. The SLN was intraoperatively identified with the aid of patent blue dye and a hand-held gamma probe. Lymphoscintigraphy showed in-transit SLNs in 59/599 patients (9.8%). During surgery, all these in-transit SLNs were harvested, with those in the popliteal and epitrochlear regions being the most difficult to identify and excise. Metastatic cell deposits were subsequently identified in ten (16.9%) of these in-transit SLNs. In conclusion, lymphoscintigraphy has a key role in the identification of in-transit SLNs. Although the incidence of these nodes is relatively low in malignant melanoma patients, such SLNs present metastatic deposits in a significant percentage of cases and therefore the identification of in-transit SLNs in these patients is really necessary.

Treatment of patients with progressive unresectable metastatic melanoma with a heterologous polyvalent melanoma whole cell vaccine.

Unresectable metastatic melanoma has no elective treatment. Neither chemotherapy, intravenous IL-2 nor biochemotherapy clearly improves the overall survival. Recent assays with therapeutic vaccines have been recently yielded promising results. Here, we describe the application, clinical tolerance and antitumoural activity of a heterologous polyvalent melanoma whole cell vaccine in patients with metastatic melanoma. Twenty-eight AJCC stage III/IV melanoma patients with progressive unresectable metastatic disease were treated with our heterologous polyvalent melanoma whole cell vaccine between July 1, 1998 and July 1, 2002. All patients had already been unsuccessfully treated with high doses of IFN-alpha2 and/or polychemotherapy and/or biochemotherapy and/or perfusion of extremities, or could not receive other treatments due to their age or underlying illness. Twenty-three were assessable. The vaccine was constituted by 10 melanoma cell lines, derived from primary, lymph node and metastatic melanomas. Prior to intradermal inoculation, the cells were irradiated and mixed with BCG, and 50% were treated with DNFB. After a median follow-up of 19 months, 26% of patients responded: 3 CR (18, 16+, and 26+ months), 2 PR (8 and 22 months) and 1 MR (36+ months). The median survival of the whole group was 20.2 months. None of the 28 patients initially included in the study presented significant toxicity. This vaccination program had specific antitumoural activity in advanced metastatic melanoma patients and was well tolerated. The clinical responses and the median survival of our group of patients, together with the low toxicity of our polyvalent vaccine, suggest that this approach could be applied to earlier metastatic melanoma patients.

Evaluation of potential liver donors: limits imposed by donor variables in liver transplantation.

The aim of this study was to evaluate the predictive value of different donor and recipient parameters that have been recognised previously as proven and to suggest prognostic factors for immediate liver function and final outcome after liver transplantation. We evaluated a total of 228 liver grafts transplanted in the last 3 years in our institution. Parameters were recorded for the donor (age, polytransfusion, atherosclerosis, presence of infection, episodes of hypoxia or hypotension, use of vasoactive drugs, intensive care unit stay, steatosis, and ischemia time) and recipient (red blood cell requirements, immediate liver function [score], incidence of hepatic artery thrombosis, survival, and cause of death or retransplantation). Liver biopsy after reperfusion of the donor liver was performed before closure of the abdomen. Donor age over 65 years and presence of steatosis were associated significantly with initial poor function. The mortality rate at 6 months was related to donor age over 65 years. When donor age over 65 years was combined with transfusion requirement of > 10 U of red blood cells (RBC), the incidence of graft loss increased to 53%. The probability of graft survival at two years decreased when donor age was over 65 years. Moreover, when donor age over 65 years was combined with requirement of > 10 units RBC the probability of 2-year survival was significantly reduced. This study shows, for the first time, that the use of donor livers from older donors in liver transplant procedures, requiring more than 10 U of RBC, results in a significantly worse prognosis in terms of immediate liver function and long-term survival.

Identification of the sentinel lymph node in patients with malignant melanoma: what are the reasons for mistakes?

Scintigraphic identification of the sentinel lymph node is achievable in nearly all patients with malignant melanoma. However, in a very small number of cases the sentinel node fails to be detected, and sometimes recurrence appears during follow-up in patients who had previously tested negative for metastatic disease. The purpose of this study was to review our experience in order to isolate the reasons for erroneous sentinel lymph node identification. The evaluation involved 435 consecutive malignant melanoma patients with AJCC stages I and II (clinically negative nodes) and Breslow thickness >0.76 mm. Lymphoscintigraphy was performed the day before surgery by intradermal administration of technetium-99m labelled nanocolloid. Dynamic and static images were obtained. The sentinel node was intraoperatively identified with the aid of patent blue dye and a hand-held gamma probe. After removal, routine histopathological examination with haematoxylin-eosin (H-E) and immunohistochemistry with S 100 and HMB45 (IHC) were performed. In those patients who developed regional recurrences during follow-up, sentinel nodes were further evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). Lymphoscintigraphy visualised at least one sentinel node in 434 out of 435 patients (99.8%). Uptake in in-transit sentinel lymph nodes was observed in 32 patients (7.4%). During surgery, localisation and removal of sentinel nodes was successful in 430/435 patients (98.8%). A total of 790 sentinel lymph nodes were harvested, with a mean of 1.8 per patient. Routine histopathological examination with H-E or IHC revealed metastatic disease in 72 patients (16.8%). During a mean follow-up of 26 months, seven of those patients with a negative sentinel node developed regional lymph node metastases. In five of them RT-PCR was positive for micrometastases within the sentinel node. In conclusion, erroneous sentinel lymph node identification can be due to changes in the surgical team, difficult lymph node location or absence of a thorough histological study. Nevertheless, it is not possible to explain completely why, in a very small percentage of cases, the sentinel node is erroneously identified.