Purpose of review:Use of gadolinium-based contrast agents (GBCA) in renal impairment is controversial, with physician and patient apprehension in acute kidney injury (AKI), chronic kidney disease (CKD), and dialysis because of concerns regarding nephrogenic systemic fibrosis (NSF). The position that GBCA are absolutely contraindicated in AKI, category G4 and G5 CKD (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m2), and dialysis-dependent patients is outdated and may limit access to clinically necessary contrast-enhanced magnetic resonance imaging (MRI) examinations. This review and clinical practice guideline addresses the discrepancy between existing Canadian guidelines regarding use of GBCA in renal impairment and NSF.Sources of information:Published literature (including clinical trials, retrospective cohort series, review articles, and case reports), online registries, and direct manufacturer databases were searched for reported cases of NSF by class and specific GBCA and exposed patient population.Methods:A comprehensive review was conducted identifying cases of NSF and their association to class of GBCA, specific GBCA used, patient, and dose (when this information was available). Based on the available literature, consensus guidelines were developed by an expert panel of radiologists and nephrologists.Key findings:In patients with category G2 or G3 CKD (eGFR ≥ 30 and < 60 mL/min/1.73 m2), administration of standard doses of GBCA is safe and no additional precautions are necessary. In patients with AKI, with category G4 or G5 CKD (eGFR < 30 mL/min/1.73 m2) or on dialysis, administration of GBCA should be considered individually and alternative imaging modalities utilized whenever possible. If GBCA are necessary, newer GBCA may be administered with patient consent obtained by a physician (or their delegate) citing an exceedingly low risk (much less than 1%) of developing NSF. Standard GBCA dosing should be used; half or quarter dosing is not recommended and repeat injections should be avoided. Dialysis-dependent patients should receive dialysis; however, initiating dialysis or switching from peritoneal to hemodialysis to reduce the risk of NSF is unproven. Use of a macrocyclic ionic instead of macrocyclic nonionic GBCA or macrocyclic instead of newer linear GBCA to further prevent NSF is unproven. Gadopentetate dimeglumine, gadodiamide, and gadoversetamide remain absolutely contraindicated in patients with AKI, those with category G4 or G5 CKD, or those on dialysis. The panel agreed that screening for renal disease is important but less critical when using macrocyclic and newer linear GBCA. Monitoring for and reporting of potential cases of NSF in patients with AKI or CKD who have received GBCA is recommended.Limitations:Limited available literature (number of injections and use in renal impairment) regarding the use of gadoxetate disodium. Limited, but growing and generally high-quality, number of clinical trials evaluating GBCA administration in renal impairment. Limited data regarding the t...

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 ...

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ACC-SRC is a nonmucin and nonlipid producing phenomenon, possibly related to disturbed differentiation of ductal/luminal cells. This cellular modification in ACC apparently does not change the biological behavior of the tumor but it may cause significant diagnostic problems, particularly in incisional biopsies. © 2012 Blackwell Publishing Ltd.