Nodal metastasis is an important prognostic indicator in head and neck cancers, including salivary carcinomas. In these, the risk for lymph node metastasis is variable and strongly associated with the tumor histologic type. The aim of the current study was to evaluate the lymphatic vessel density (LVD) and expressions of lymphangiogenic growth factors by tumor cells in different histologic types of salivary carcinomas subdivided according to the risk for nodal metastasis. In 15 high-risk (undifferentiated, high-grade mucoepidermoid and salivary duct carcinomas) and 60 low/moderate-risk tumors (adenoid cystic, low/intermediate-grade mucoepidermoid, acinic cell, myoepithelial, epithelial-myoepithelial and polymorphic lowgrade carcinomas) the expressions of vascular endothelial growth factor-C (VEGF-C), hepatocyte growth factor (HGF) and D2-40 (for assessing LVD) were examined. No significant differences were encountered between high-and low/moderate/-risk carcinomas regarding LVD and VEGF-C or HGF expressions. Furthermore, the expression of these proteins did not correlate with LVD. Lymphatic vascular invasion was found mainly in high-risk carcinomas. Intratumoral LVD was significantly lower than peritumoral, regardless of the risk for metastasis and primary site of the lesion. The histologic types of salivary carcinomas which are associated with high-risk for nodal metastasis do not present increased LVD or VEGF-C and HGF expressions. The greater tendency for metastasis in these carcinomas seems to be related to their capacity to invade lymph vessels. Further studies on tumor cell interactions with lymphatic endothelial cells are needed to improve our understanding of the metastatic potential of salivary carcinomas. Key words: lymph vessels, salivary carcinoma, VEGF-C, HGF.Nodal metastasis is an important prognostic predictor in head and neck cancers, including salivary carcinomas. The risk for lymph node metastasis in these carcinomas is highly variable (9% -85%) [1] and strongly associated with the tumor histologic type [1][2][3][4][5]. It is a general consensus that high-grade mucoepidermoid carcinomas, salivary duct carcinomas, undifferentiated carcinomas and squamous cell carcinomas are high-risk tumors for nodal metastasis [1,[3][4][5]. In these the risk for neck metastasis has been described to be >50% [1] and, thus, elective neck dissection is considered in their management [1][2][3].Lymph vessels provide the main avenue for nodal metastasis and in head and neck squamous cell carcinoma (HNSCC) it has been shown that tumors of different anatomic regions do not vary significantly in their lymphangiogenic properties [6,7]. However, a high lymph vessel density (LVD) seems to be an indicator of the risk of lymph node metastasis in HNSCC [6][7][8][9]. Regarding salivary gland tumors, the lymphatic vessels have rarely been studied [10][11][12] and in a particular type of salivary carcinoma, i.e. in those arising in pleomorphic adenomas (CXPA) the lymphatic network was found to be composed mainly of pre-existing ...

_______________________________________________________________________________________Introduction: Horseshoe kidney occurs in 1 per 400-800 live births and are more frequently observed in males (M:F 2:1). Ureteropelvic junction obstruction (UPJO) is commonly associated with horseshoe kidneys. The variable blood supply, presence of the isthmus and high insertion of the ureter contribute to this problem. Case report: An asymptomatic 6 year-old boy presented with antenatal hydronephrosis. Ultrasonography and CT scan demonstrated left UPJO associated with a horseshoe kidney. DMSA showed 33% of function on the left side. DTPA showed a flat curve and lack of washout. A left dismembered laparoscopic pyeloplasty was performed after identification of crossing vessels and abnormal implantation of the ureter. After one year, the child is asymptomatic. DTPA demonstrated a good washout curve. Results: Our cohort consisted of six patients, five males and one female, with a mean age of 6 years (range 6m-17 years) and a mean follow-up of 3 years. Ureteropelvic junction obstruction was more common on the left side. Symptoms appeared only in 34% of the cases. Mean operative time was 198 minutes (range 120-270 minutes). Crossing vessels were common (observed in 50% patients). High implantation of ureter was seen in 67% patients and intrinsic obstruction in 83%. Surgical difficulties were found in two cases. Hospital stay was 4.3 days (3 to 6 days), with only one patient having a mild complication (pyelonephritis). All cases had clinical and radiologic improvement. Conclusion: Laparoscopic pyeloplasty is safe and feasible in children with UPJO in horseshoe kidneys, with good results and minimal morbidity. ARTICLE INFO