Effects of the number of removed lymph nodes on survival outcome in patients with sentinel node-negative breast cancer.

BACKGROUND: Sentinel lymph node biopsy is the gold standard surgical technique for axillary staging in patients with clinically node-negative. However, it is still uncertain what is the optimal number of sentinel lymph nodes (SLNs) to be removed to reduce the false-negative rate. The aim of this study was to investigate whether patients with a single negative SLN have a worse prognosis than those with two or more negative SLNs. METHODS: A retrospective review was conducted on a large series of SLN-negative breast cancer patients. Survival outcomes and regional recurrence rate were evaluated according to the number of removed SLNs. Secondly, the contribution of different adjuvant therapies on disease-free survival was explored. Statistical analysis included the chi-square, Wilcoxon-Mann-Whitney test, and Kaplan-Meier survival analysis. RESULTS: A total of 1080 patients were included in the study. A first group consisted of 328 patients in whom a single SLN was retrieved, and a second group consisted of 752 patients in whom two or more SLNs were retrieved. There was no relevant difference in median DFS (64.9 vs 41.4) for SLN = 1 vs SLN > 1 groups (HR 0.76, CI 95% 0.39-1.46; p = 0.38). A statistically significant difference in mDFS was showed only for HT-treated patients who were SLN = 1 if compared to SLN > 1 (100.6 months versus 35.3 months). CONCLUSIONS: There is likely a relationship between the number of resected SNL and mDFS. Our results, however, showed no relevant difference in median DFS for SLN = 1 vs SLN > 1 group, except for a subset of the patients treated with hormone therapy.

Value of Neurostimulation Plus Laryngeal Palpation to Predict Postoperative Vocal Fold Motility.

BACKGROUND: The aim of this study was to evaluate the reliability of intraoperative neuromonitoring through recurrent laryngeal nerve stimulation and simultaneous laryngeal palpation (NSLP) in predicting postoperative vocal cord palsy and in providing useful information in the decision to perform a staged surgery in initially planned total thyroidectomy. MATERIALS AND METHODS: A retrospective review was performed involving 552 patients for whom a total thyroidectomy was planned. In all patients, preoperative and postoperative laryngoscopy was performed. The incidence of vocal cord palsy was calculated on 1104 nerves at risk. RESULTS: Sensitivity and specificity of NSLP were 0.9411 and 0.9925 respectively. The positive predictive value was 0.7804, the negative predictive value was 0.9981, the false positive rate was 0.8%. In 41 patients (7.4%) the initial surgical strategy was changed into a staged procedure. Nine patients (21.9%) were false positive, 32 patients (78.1%) were true positive. Finally, a two-stage thyroidectomy was performed in 27 of 41 patients. CONCLUSIONS: High sensitivity and specificity confirm the validity of NSLP in predicting postoperative vocal cord palsy and in driving a possible staged thyroidectomy, both in benign thyroid disease and in differentiated thyroid carcinoma.

Safety and Feasibility of Robotic-Assisted Drainage of Symptomatic Pancreatic Pseudocysts: A Case-Series Analysis (with video).

Background: The surgical treatment of pancreatic pseudocysts (PPs) in patients who fail nonoperative management has evolved from aggressive open to a minimally invasive approach. The application of robotic surgery in this setting is scarcely reported. The aim of this study is to analyze the safety and feasibility of the robotic approach to pancreatic pseudocyst drainage. Methods: A single centre retrospective review of consecutive patients undergoing robotic-assisted pancreatic pseudocyst surgeries in an academic tertiary institution was performed. Results: There were 14 patients studied, of whom 10 underwent cystogastrostomy and 4 Roux-En- Y cystojejunostomy. Eight patients had gallstone pancreatitis and 3 patients alcoholic pancreatitis. The mean size of cyst was 8.9 +-1cm and 57.1% located at the pancreatic body. The overall operative time of the procedure was 135 +-34 minutes. There were no open conversions. The overall success rate was 92.8%, while the primary success rate 85.7%. The major morbidity rate was 14.3% and there was no 30-day mortality. The mean post-operative hospital stay was 7 +-3 days with one recurrence of the pancreatic pseudocyst on follow-up requiring endoscopic drainage without further recurrence. Conclusions: The robotic approach for the drainage of symptomatic pancreatic pseudocyst is safe and feasible and can be considered as a viable modality for operative intervention in well-selected patients.

Laryngopharyngeal reflux as a potential cause of persistent local neck symptoms after total thyroidectomy.

PURPOSE: Local neck symptoms (LNS) may be related to goiter, but are also reported by patients suffering from laryngeal-pharyngeal reflux (LPR). The aim of this study was to investigate whether LPR could play a role in the persistence of some LNS after total thyroidectomy (TT). METHODS: A consecutive case series of 160 patients with multinodular goiter (MNG) candidate for TT were included in this study. Each patient was closely studied for both the thyroid pathology and reflux disease before and 6 months after surgery to assess the persistence of LNS after surgery. RESULTS: Only throat discomfort showed a significant improvement (p = 0.031) after surgery. On the other hand, swallowing and voice disorders persisted after surgery in 82.3% and 77.3% of patients, respectively (p = 0.250 and p = 0.062), such as the correlated reflux laryngopharyngitis (p = 0.5). CONCLUSIONS: LPR can be considered a predisposing factor or an important concurrent causa to the persistence of LNS after TT, in particular for swallowing disorders and voice disorders. In patients with non-toxic MNG who complain of local neck symptoms, the investigation of a possible coexistence of a reflux disease is appropriate before surgery. Patients should be informed about the possibility that some symptoms can persist even after removal of the goiter.

Laparoscopic versus robotic right colectomy with extra-corporeal or intra-corporeal anastomosis: a systematic review and meta-analysis.

PURPOSE: The aim of the present systematic review and meta-analysis is to compare laparoscopic right colectomy (LRC) versus robotic right colectomy (RRC) using homogeneous subgroup analyses for extra-corporeal anastomosis (EA) and intra-corporeal anastomosis (IA). METHODS: MEDLINE, Scopus, and Web of Science databases were searched up to April 2020 for prospective or retrospective studies comparing LRC versus RRC on at least one short- or long-term outcome. The primary outcome was the length of hospital stay (LOS). The secondary outcomes included operative and pathological results, survival, and total costs. LRC and RRC were compared using three homogeneous subgroups: without distinction by the type of anastomosis, EA only, and IA only. Pooled data analyses were performed using mean difference (MD) and random effects model. RESULTS: Thirty-seven of 448 studies were selected. The included patients were 21,397 for the LRC group and 2796 for the RRC group. Regardless for the type of anastomosis, RRC showed shorter LOS, lower blood loss, lower conversion rate, shorter time to flatus, and lower overall complication rate compared with LRC, but longer operative time and higher total costs. In the EA subgroup, RRC showed similar LOS, longer operative time, and higher costs compared with LRC, the other outcomes being similar. In the IA subgroup, RRC showed shorter LOS and longer operative time compared with LRC, with no difference for the remaining outcomes. CONCLUSIONS: Most included articles are retrospective, providing low-quality evidence and limiting conclusions. The more frequent use of the IA seems to explain the advantages of RRC over LRC.

Impact of BMI on Preoperative Axillary Ultrasound Assessment in Patients With Early Breast Cancer.

BACKGROUND: The accuracy of axillary ultrasound (AUS) with fine-needle aspiration with varying patient body mass index (BMI) is still unclear. The aim of our study was to evaluate whether the US features of axillary lymph nodes changes with BMI of patients. PATIENTS AND METHODS: A retrospective review was performed involving 144 out of 270 patients with early breast cancer who underwent breast surgery with sentinel lymph node biopsy. Diagnostic efficacy of AUS in preoperative axillary nodal staging was assessed in relation to BMI. RESULTS: Negative predictive values of AUS for the overweight and obese groups were statistically significantly lower compared to the normal/underweight group (p=0.02 and p=0.003, respectively). Additionally, Spearman's correlation coefficient R between BMI and positive sentinel lymph node biopsy was 0.257, suggesting a significantly positive linear relationship between the two variables in the cohort overall. CONCLUSION: Our results demonstrate how in our cohort the negative predictive value of AUS was significantly influenced by adipose tissue and that the selection of the most suitable instrumental diagnostic technique might contribute to improving heterogeneous results.

Robotic-assisted pancreaticoduodenectomy with vascular resection. Description of the surgical technique and analysis of early outcomes.

BACKGROUND: Despite the potential benefits, the adoption of the minimally invasive surgery for the treatment of borderline resectable pancreatic cancer is still in the initial phase. We investigated the safety and feasibility of the robotic pancreaticoduodenectomy with venous resection/reconstruction (RPD SMV/PV). METHODS: Since March 2013 to October 2019, a total of 73 RPD and 10 RPD SMV/PV were performed. The two groups were case-matched according to the preoperative characteristics. RESULTS: Mean operative times and estimated blood loss were less in the RPD group in comparison to that in the RPD with SMV-PV group (525 vs 642 min, p = 0.003 and 290 vs 620 ml, p = 0.002, respectively). The mean length of hospital stay was similar in the RPD group in comparison to that in the RPD with SMV-PV group (10 days vs 13 days, p = 0.313). The two groups had similar overall postoperative morbidity rate (57.5% vs 60%, p = 0.686), although the severe complication rate was lower in the RPD group (11% vs 40%, p = 0.004). CONCLUSIONS: RPD with SMV-PV is associated with increased operative time, estimated blood loss, higher major complication rate compared with RPD.

Tangential Venous Resections during Robotic-Assisted Pancreaticoduodenectomy: the Results of a Case Series (with Video).

INTRODUCTION: Despite the potential advantages in terms of microdissection and microsuturing capabilites, the robotic approach for borderline resectable pancreatic cancer is scarcely reported. METHODS: We report our technique for a robotic-assisted pancreaticoduodenectomy with tangential Portal/ Superior Mesenteric Vein resection/reconstruction (RPD PV/SMV).We also compared the surgical outcomes of eight consecutive patients undergoing RPD PV/SMV with that of sixty patients who underwent robotic-assisted pancreaticoduodenectomy (RPD) in the same period of time. RESULTS: A total of eight consecutive patients underwent RPD PV/SMV. We observed an increased estimated blood loss (550 vs 280 mL, p = 0.003) and operative time (438 vs 350 min, p = 0.002) in the RPD PV/SMV group of patients compared with RPD group, whereas the complication rate (28% vs 31%, p = 0.726) was similar. No venous-congestion related complications were observed in the postoperative course. The median length of hospital stay was similar in the RPD group in comparison to that in the RPD PV/SMV group (10 vs 13 range 6-19 days, p = 0.313). CONCLUSION: RPD PV/SMV is a challenging operation. It is associated with higher operative time and increased estimated blood loss in comparison to standard RPD.

Axillary Nodal Burden in Breast Cancer Patients With Pre-operative Fine Needle Aspiration-proven Positive Lymph Nodes Compared to Those With Positive Sentinel Nodes.

BACKGROUND/AIM: Recent years have seen a considerable shift to a more conservative management of the axilla in patients with positive axillary sentinel lymph nodes. The aim of this study was to determine whether some breast cancer patients with a preoperative ultrasound-guided needle aspiration biopsy proven positive node could potentially be spared an axillary lymph node dissection according to the ACOSOG Z0011 trial criteria. PATIENTS AND METHODS: A retrospective review was performed involving 623 breast cancer patients who underwent axillary lymph node dissection after either ultrasound-guided needle aspiration biopsy proven positive node or sentinel lymph node biopsy. RESULTS: Patients with fine needle aspiration biopsy-proven positive node had worse prognosis and a higher nodal burden (6.7 vs 1.9 nodes, p<0.001), compared to those with positive sentinel lymph nodes. CONCLUSION: Patients with an ultrasound guided needle aspiration biopsy proven positive node are more likely to have tumor with more aggressive pathological characteristics and a higher nodal burden than those with a positive sentinel lymph node biopsy.

Current Role of Intraoperative Frozen Section Examination of Sentinel Lymph Node in Early Breast Cancer.

BACKGROUND/AIM: The aim of this study was to evaluate the current role of frozen section in identifying patients who could benefit from an immediate axillary lymph node dissection (ALND), following the criteria of the ASOCOG Z0011 and IBCSG 23-10 trials. PATIENTS AND METHODS: A retrospective review was performed involving 2,079 patients with early breast cancer who underwent conservative surgery or total mastectomy with sentinel lymph node biopsy. RESULTS: Sensitivity and diagnostic accuracy were 63.8% and 90.3%, respectively. Sensitivity was significantly higher (p<0.001) in finding macrometastases (81.8%) compared to micrometastases (11.9%). Frozen section was useful only in 7.7% of the patients who met the criteria of the IBCSG 23-01 and ACOSOG Z0011 trials. CONCLUSION: Frozen section continues to be very useful in the intraoperative assessment of the SLN, offering a high sensitivity and diagnostic accuracy. Omission of ALND in 24.4% of patients who met the ACOSOG Z0011 criteria would have resulted in their undertreatment.

Mitochondrion at the Crossroad Between Nutrients and Epigenome.

Epigenetic profile is the link between the regulation of nuclear gene expression and the environment. The most important factors capable of significantly affecting the cellular environment are the amount and quality of nutrients available. Mitochondria are both involved in the production of some of the molecules capable of directly affecting the epigenome and have a critical role in the conversion of nutrients into usable energy. Carbohydrate and fats are converted into ATP, acetyl-CoA, SAM, and NADH. These high-energy substrates are, in turn, capable of driving the epigenetic profile. We describe substances capable of affecting this mechanism. On the other hand, nutritional interventions capable of reducing calories or significantly impairing the normal Acetyl-CoA production or the SAM-SAH ratio also impact chromatin methylation and histone modification, suggesting a critical role of mitochondria on nutrient-dependent epigenetic profile.

Denosumab for bone health in prostate and breast cancer patients receiving endocrine therapy? A systematic review and a meta-analysis of randomized trials.

Hormonal therapies for receptor positive-breast and prostate cancer patients have shown clinical efficacy but also several side effects including osteoporosis, loss of bone mass and increased fracture risk. Denosumab represents an anti RANKL (receptor activator of nuclear factor-kB ligand) monoclonal anti-body acting as inhibitor of osteoclasts formation, function, and survival, then increasing bone mass. Herein, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the role of Denosumab in saving bone health in prostate and breast cancer patients receiving respectively androgen deprivation therapy and adjuvant endocrine therapy. Moreover, selected patients have to be treated with Denosumab at the dose of 60 mg every six month or placebo. Outcomes studied included the bone mass density (BMD) increase at 24 and 36 months, BMD loss, reduction of fractures risk (in particular vertebral) at 24 and 36 months and safety (overall, serious adverse events - SAEs and discontinuation rate). Our results showed a reduction of the BMD loss up to 36 months both at the lumbar and femoral level and a BMD increase both at 24 and 36 months. It was also found a reduction in the number of new vertebral and femoral fractures at 24 and 36 months. Finally, our pooled analysis showed that Denosumab did not affect both the SAEs and therapy discontinuation risk. In conclusion, Denosumab administration can be considered effective and safe in the prevention and management of the above mentioned adverse events related to hormonal therapies designed for breast and prostate tumors.

Association between Hashimoto's thyroiditis and papillary thyroid carcinoma: a retrospective analysis of 305 patients.

BACKGROUND: The association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) is a controversial question that is still under debate, its pathological significance and the eventual clinical implications of this association remaining unclear. METHODS: The data regarding 305 patients were retrospectively analyzed. The patients were divided in two different groups. A first group made up of 142 patients undergoing surgery for differentiated thyroid carcinoma was compared to a control group of 142 analogous subjects operated for normofunctioning goiter. A second group was made up of 163 patients who had undergone total thyroidectomy (TT) with pre-operative diagnosis of HT. RESULTS: In the first group of patients an association with HT was found in 28,6% of the patients with final histopathological diagnosis of PTC versus 7,7% of the patients with histopathological diagnosis of multinodular goiter, which was a significant difference (p <  0.001). In the second group, the association with PTC was found in 43 (40,2%) cases of HT nodular variant and in 3 cases (8,1%) of HT diffuse variant (p <  0.001). CONCLUSIONS: The relationship between HT and PTC is still far from clear and represents an unresolved issue. Our own study has underlined the frequent coexistence of these two pathologies, an aspect not to be neglected in clinical practice. Patients receiving HT diagnosis should undergo careful follow-up and, especially those with the nodular variant, should undergo a frequent both clinical and cytological evaluation of the nodular lesions, taking always into great consideration the surgical approach of total thyroidectomy.

The value of total thyroidectomy as the definitive treatment for Graves' disease: A single centre experience of 594 cases.

PURPOSE: Thyroidectomy is the preferred approach as the definitive treatment for Graves' disease. The outcomes for total thyroidectomy in a large series of 594 patients, who were observed in the last decade, will be presented in this study. METHODS: The study concerned a retrospective review of 594 patients, undergoing a total thyroidectomy for Graves' disease. The incidence of complications and outcomes on hyperthyroidism and correlated symptoms resolution were also evaluated. RESULTS: The mean age of the patients was of 44.7 ±â€¯12.7 years and 456 patients (76.7%) were females. The mean gland weight was 67.3 ±â€¯10.8 g (range: 20-350 g) and, in 397 patients (66.8%), the gland weighed >40 g. The mean operative time was 125 ±â€¯23.1 min (range: 65-212 min). Temporary and permanent hypocalcaemia developed in 241 (40.6%) and 3 patients (0.5%), respectively. Temporary and permanent recurrent laryngeal nerve palsy were recorded in 31 (5.2%) and 1 patients (0.16%) respectively. No patient developed a thyroid storm. On multivariate analysis, patient age ≤50 years (Odds ratio: 1; 95% Confidence Interval: 0.843-0.901) and thyroid weight >40 g (Odds ratio: 1; 95%, Confidence Interval: 0.852-0.974), were mainly associated with the occurrence of complications. CONCLUSION: This high-volume surgeon experience demonstrates that total thyroidectomy is a safe and effective treatment for Graves' disease. It is associated with a very low incidence rate of post-operative complications, most of which are transitory; therefore, it offers a rapid and definitive control of hyperthyroidism and its related symptoms.

An evaluation score of the difficulty of thyroidectomy considering operating time and preservation of recurrent laryngeal nerve.

The purpose of this study was to edit a renovated thyroidectomy difficulty scale (rTDS) in order to identify underlying thyroid diseases with a longer operative time and higher technical difficulty, also considering preservation of recurrent laryngeal nerve. We developed a renovated scale with a maximum score of 20 points by creating a form in which five variables were considered: vascularity, friability, mobility/fibrosis, gland size and difficulty in preservation of the recurrent laryngeal nerve. Two surgeons separately evaluated each of these. Through a simple linear regression analysis, we have analyzed the relationship between rTDS score and operative times, and between rTDS score and preservation of recurrent nerve. Eventually, Spearman's rank correlation coefficient has been used in order to evaluate our double-blind study. Our cohort included 131 patients undergoing total thyroidectomy. The mean of the rTDS was 9.00 ± 3.67 for Surgeon A and 8.31 ± 3.42 for Surgeon B, with Spearman's rank correlation coefficient between surgeons of 0.85 (p < 0.0001). We have shown that the rTDS score significantly influences the operating times (R2 = 0.44 for surgeon A, R2 = 0.46 for B, p < 0.0001 for both). Moreover, we can say that the rTDS score significantly influences preservation of the recurrent nerve (R2 = 0.37, Beta 0.61, 8.84 t test, p < 0.0001). Our rTDS is a useful tool and, thanks to it, we identified hyperthyroidism and goiter as the hardest underlying disease for surgery. Thus our scale could change operative approach, resulting in better surgeries' scheduling and identification of pathologies that require higher attention.

Ultrasound-Guided Breast-Conservative Surgery Decreases the Rate of Reoperations for Palpable Breast Cancer.

The purpose of this study is to verify whether the performance of ultrasound-guided quadrantectomy (USGQ) versus palpation-guided quadrantectomy (PGQ) can reduce the incidence of positive margins and if it can change the attitude of the surgeon. A retrospective study was conducted on 842 patients underwent quadrantectomy for breast cancer, 332 of them underwent USGQ, whereas 550 underwent PGQ. The histological type of the tumors and the margin status obtained with the histological examination were compared. The histological examination of the surgical specimen showed involvement of the margins in 24/842 patients (2.85%), 22 (2.61%) of them belonged to the PGQ group, and two to the USGQ group (P = 0.0011). The highest rate of microscopically positive margins was, statistically significant, for carcinoma in situ, when compared with patients with invasive carcinoma (0.0001). USGQ technique showed several advantages compared with PGQ. In fact, the former notes a lower positive margin rate and, consequently, a lower rate of reintervention. In addition, it may change the surgeon's attitude by causing him to remove another slice of margin to ensure more histological negativity. It should be the gold standard technique for breast-conservative surgery of palpable tumors.

Thyroid metastases from renal cell carcinoma. Report of a case and review of the literature.

Metastases to thyroid gland are a rare occurrence in surgical practice. The most frequent primitive tumor is renal cell carcinoma. We report a case of thyroid metastasis from renal cell carcinoma in a 70-year-old man who underwent left nephrectomy ten years earlier, presented with a diagnosis of multinodular goiter, associated with thyroiditis and right laterocervical lymphadenopathy. A total and the surgical excision of laterocervical lymph node were performed. The results, according to the histological examination, were metastases from renal cell carcinoma, involving both the thyroid gland and the lymph node. Therefore, since the delay of presentation and the difficulties of diagnosis, we recommend log-term follow-up of the head and neck region, for those patients with renal cell carcinoma diagnosis.

Completion axillary lymph node dissection can be avoid in patients with invasive breast cancer and sentinel lymph node micrometastases.

BACKGROUND: The prognostic value of sentinel lymph node (SLN) micrometastases in invasive breast cancer patients is still widely debated. Even if, in the absence of unequivocal guidelines, the axillary lynphadenectomy is not still performed in the routine clinical care of these patients. MATERIALS AND METHOD: We have retrospectively analyzed 897 patients with operable invasive breast cancer and clinically negative axillary lymph nodes underwent conservative surgery or total mastectomy with SLN biopsy. Two groups of patients with SLN micrometastases and isolated tumor cells (ITC) were considered, the first one treated with completion axillary dissection, the second one not followed by further surgical axillary procedure. The incidence of axillary recurrences has BEEN evaluated in both groups and only in the first group of patients the involvement of the remaining lymph nodes was analyzed. RESULTS: Micrometastases were found in 67 (7.4%) patients and ITC in 8 (0,9%) patients. 14 (20.9%) patients with micrometastases and 1 (12.5%) patient with ITC underwent completion axillary dissection. 53 (79.1%) patients with micrometastases and 7 (87.5%) with ITC didn't receive further surgical axillary procedure. No axillary recurrences were found during a median follow up of 65.7±8.69 months in both groups of patients. CONCLUSIONS: Based on the results and according to some recent randomized trials we can say that completion axillary dissection can be safely avoided when micrometastases are found in sentinel lymph nodes. It should be performed anyway, depending on the analysis of the biomedical profile of the tumor. KEY WORDS: Breast Carcinoma, Micrometastases Axillary Lymphonode Dissection, Sentinel Lymphonode.

Application of a predictive model of axillary lymph node status in patients with sentinel node metastasis from breast cancer. A retrospective cohort study.

BACKGROUND AND OBJECTIVES: The Axillary Lymph Node Dissection (ALND) is the standard treatment in patients with invasive breast cancer and sentinel node metastasis, but in 60% of the cases there is no further axillary neoplastic involvement, so this invasive intervention represents an overtreatment. The purpose of the study is to identify patients with low risk of additional nodal metastases, to omit ALND. METHODS: The MSKCC Additional nodal metastasis nomogram was applied on a sample of 175 patients with invasive breast cancer who underwent ALND after detection of macrometastasis with the extemporaneous examination of the sentinel lymph node. Patients were classified as "low risk" when the result of the nomogram was ≤50%. Sensitivity, specificity, positive and negative predictive values and AUC (Area Under Curve) of the ROC curve of the nomogram were then calculated. RESULTS: A cut-off by 50% yielded 92.3% sensitivity, 81,4% specificity, 80% positive predictive value and 92.9% negative predictive value. The ROC curve AUC in these patients was 0.885. CONCLUSIONS: The MSKCC nomogram has proven to be an effective tool in estimating the axillary lymph node status and it can potentially be used to better select the patients with sentinel node macrometastasis who can actually benefit from ALND.

Lymphoscintigraphy with peritumoral injection versus lymphoscintigraphy with subdermal periareolar injection of technetium-labeled human albumin to identify sentinel lymph nodes in breast cancer patients.

BACKGROUND: Preoperative lymphoscintigraphy is without doubt a valid method for the detection of the sentinel lymph node (SLN). There has been considerable debate regarding the optimal site for the introduction of the tracer; various sites include peritumoral (PT), periareolar (PA), subdermal, and intradermal injection. PURPOSE: To evaluate retrospectively the lymphoscintigraphic identification rate of peritumoral (PT) injection versus subdermal periareolar (PA) injection in the detection of SLNs in breast cancer. MATERIAL AND METHODS: Between October 2002 and December 2011, a cohort of 906 consecutive patients with biopsy proven breast cancer underwent 914 SLN biopsy procedures. A total of 339 procedures (Group A) were performed using a PT deep injection of radiotracer while 575 procedures (Group B) adopted a subdermal PA injection of radiotracer towards the upper outer quadrant, regardless of the site of the carcinoma. All the patients underwent synchronous excision of the breast cancer and SLN biopsy. RESULTS: SLNs were identified in the lymphoscintigram in 308/339 cases (90.85%) of Group A (PT injection) and in 537/575 cases (93.39%) of Group B (PA injection). Furthermore, in 2/339 patients (0.58%) of Group A, internal mammary lymph nodes were found at lymphoscintigraphy, whereas no internal mammary sentinel nodes were found in the Group B patients. The intraoperative identification rate of axillary SLNs was 99.41% (337 of 339) in the Group A patients and 99.65% (573 of 575) in the Group B patients. There was no significant difference in the two groups between the incidence of the number of SLNs detected and the incidence of identification of positive SLNs. CONCLUSION: PT versus PA injection of radiotracer showed comparable success rates for axillary SLN identification, and can be considered a rapid and reliable method.