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The sarcomatoid variant of renal cell carcinoma is a highly aggressive tumor with propensity for metastasis and limited therapeutic options. Metastases of sarcomatoid renal cell carcinoma can sometimes be mistaken for a variety of spindle cell sarcomas, particularly at soft tissue sites in the absence of a history of a kidney tumor. Immunoreactivity for markers associated with certain types of soft tissue sarcomas can, therefore, pose a pitfall for diagnosis under such circumstances. We evaluated the immunohistochemical and molecular features of 49 cases of sarcomatoid renal cell carcinoma with special emphasis on the expression of MDM2 by immunohistochemistry and MDM2 amplification by fluorescence in situ hybridization. Of the 49 sarcomatoid renal cell carcinoma cases evaluated by fluorescence in situ hybridization, 5 (10%) were positive for MDM2 gene amplification and 5 (10%) contained polysomy 12. Immunohistochemical nuclear expression for MDM2 was also observed in 30/49 (61%) cases; of these, 15/19 (78%) were metastatic and 15/30 (50%) were primary. MDM2 expression by immunohistochemistry has been previously reported in conventional clear cell renal cell carcinoma; however, occurrence of this phenomenon has not yet been properly assessed in the sarcomatoid variant of renal cell carcinoma. Our study demonstrates that alterations of the MDM2 pathway are relatively frequent in sarcomatoid renal cell carcinoma, and nuclear positivity for MDM2 by immunohistochemistry, as well as MDM2 amplification by fluorescence in situ hybridization may pose a potential pitfall for diagnosis with dedifferentiated liposarcoma at metastatic sites. A panel approach to immunohistochemical testing is recommended for the diagnosis of these lesions. Also, identification of cases of sarcomatoid renal cell carcinomas harboring MDM2 copy number gain or gene amplification may also have potential therapeutic implications., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Hypertension in subjects on long term dialysis is frequent. Its origins are found in extracellular volume overload, which is complicated by increased peripheral arterial resistance. The latter is affected by many systems, including that of renin-angiotensin, endothelin, nitric oxide, the sympathetic nervous system, and others. The interaction between these factors may explain why the control of hypertension in dialysis patients requires ongoing attention to the many aspects of good dialysis.

In spite of its universal acceptance, the international classification of epileptic seizures suffers from certain limitations. The fundamental divisions between partial and generalized seizures on the one hand, and between partial simple and complex seizures on the other, are not always practical, nor useful. The terminology is often cumbersome, and does not contain essential localizing information. Finally, the seizure classification is sometimes dependent on ancillary testing, particularly the EEG. We propose a different seizure classification, which answers the above shortcomings of the international classification, and which has been used for years in major epilepsy centers. In this system, the seizure classification is based exclusively on seizure symptomatology. The terms are generally more concise than those of the international classification, and yet convey more precise information. For example, the term left visual aura-->automotor seizure-->generalized tonic clonic seizure would be equivalent to simple partial seizure with visual symptom evolving into complex partial seizure evolving into generalized tonic clonic seizure. The international classification is longer and omits essential later-alizing information. This classification is easy to apply, and can be an extremely useful complement to the international seizure classification, especially for centers whose emphasis is on surgical treatment of epilepsy.