Imaging Features of Succinate Dehydrogenase-deficient Pheochromocytoma-Paraganglioma Syndromes.

Pheochromocytoma (PC) and paraganglioma (PGL) are rare neuroendocrine tumors that occur throughout the body from the base of the skull to the pelvis. Sympathetic catecholamine-secreting tumors may be associated with hyperadrenergic symptoms and long-term morbidity if they are untreated. Typically biochemically silent, head and neck PGLs may result in cranial nerve palsies and symptoms due to localized mass effect. Tumors can arise sporadically or as part of an inheritable PC-PGL syndrome. Up to 40% of tumors are recognized to be associated with germline mutations in an increasing array of susceptibility genes, including those that appear to arise sporadically. Most commonly, up to 25% of all PC-PGLs are associated with mutations in one of the succinate dehydrogenase (SDH) enzyme subunit genes. The resulting familial PC-PGL syndrome varies according to the affected enzyme subunit (most commonly SDHB and SDHD mutations) with respect to tumor prevalence, location, age of onset, and risk of malignancy. Patients with SDH enzyme mutations have increased lifetime risk of developing multifocal tumors and malignancy. Early recognition of individuals at high risk, genetic testing, screening of family members, and lifelong surveillance programs are recommended, but not without health, economic, and psychologic implications. Anatomic and functional imaging is key to diagnosis, staging, treatment planning, and lifelong surveillance of these individuals. Radiologists must be aware of the imaging appearance of these varied tumors.©RSNA, 2019.

Role of superficial femoral artery stents in the management of arterial occlusive disease: review of current evidence.

The objectives of this study were to compare the 1-year patency of superficial femoral artery (SFA) stent placement with percutaneous transluminal angioplasty (PTA) alone and to attempt to define the role of stents in arterial occlusive disease. Literature searches of the Embase, Medline, and Cochrane databases identified relevant articles, which were split into two subgroups: those containing case-controlled matches for stenting and PTA and those considering only stent placement. The review conformed to the QUORUM statement. One-year patency rates were 219 of 383 (57%) in the stented group and 319 of 607 (53%) in the PTA group for matched cases (odds ratio 1.206 [95% CI 0.932-1.559; p = .115]). The patency of stents deployed secondarily was 554 of 909 (61%). The combined 1-year patency of primary and secondary SFA stents for matched and unmatched case series was 816 of 1,282 (64%). One-year patency rates following stent placement or PTA alone in well-matched patient groups demonstrated no significant difference. This would suggest that the routine use of primary SFA stenting should be undertaken only in selected cases and should mainly be used in "bailout" situations or for complex lesions where surgery is precluded. However, the studies used displayed a high degree of heterogeneity, and some used stent technology that is now considered obsolete. Ongoing randomized controlled trials will provide a more definitive answer to this important problem.