Renal tumor with overlapping distal nephron morphology and karyotype.
ABSTRACT Although most renal epithelial tumors are derived from the proximal nephron, approximately 10% are believed to originate in the distal nephron. This latter group encompasses oncocytoma, chromophobe renal cell carcinoma, and several rare types, including collecting duct carcinoma and renal medullary carcinoma. Despite progress in the classification of renal tumors, a small subset of renal carcinomas remains unclassified (ie, renal cell carcinoma, not otherwise specified). We describe a metastatic tumor consisting of cells with overlapping distal nephron morphologies, including foci of oncocytoma, chromophobe renal cell carcinoma, and collecting duct carcinoma, as well as sarcomatoid dedifferentiation. Special stains were inconclusive, and ultrastructural study demonstrated abundant mitochondria and no microvesicles. The karyotype was hypodiploid with 41 chromosomes and abnormalities reported in all 3 phenotypes present. Rearrangements of 1p and of 11q13 previously seen in divergent subsets of oncocytomas were concomitantly present in the current tumor. Thus, this malignancy has features consistent with distal nephron derivation and demonstrates the convergence of the varied tumor morphologies arising within this site. Furthermore, this case exemplifies the value of cytogenetic analysis in the characterization of renal cell carcinoma, not otherwise specified. In view of recent advances in treatment approach, especially for collecting duct carcinoma, further categorization of this nondescript and heterogeneous group of renal cell carcinomas, not otherwise specified, at least by its derivation in relationship to the renal nephron (distal vs proximal), may be of value in the choice of treatment modality.
SourceAvailable from: Jose I Lopez
Article: La médula renal normal y patológica[Show abstract] [Hide abstract]
ABSTRACT: Background The renal medulla is composed of a complex system of tubules, blood vessels and interstitium, which the general pathologist often are unfamiliar with. Methods An in depth review of the literature and of material from our archives related to the pathology of the renal medulla was made. Results Interesting data on normal and abnormal development, microscopic anatomy, histology, immunohistochemistry, physiology, and pathology, including renal medulla differentiation disorders (multicystic renal dysplasia, adult and infantile type polycystic diseases, cystic medullary disease), inflammatory diseases (xanthogranulomatous pyelonephritis, malakoplakia) and neoplasias (oncocytoma, atypical oncocytic tumour, chromophobe renal cell carcinoma, collecting duct carcinoma, urothelial carcinoma, other carcinomas, renomedullary fibroma and metastatic tumours), was reviewed. Conclusions A comprehensive knowledge of the genesis, function, and pathology of the renal medulla would result in a greater interest being taken in an area often ignored by pathologists.10/2009; 42(4). DOI:10.1016/S1699-8855(09)70193-X
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ABSTRACT: USEFULNESS OF THE PRESENT RENAL CELL CARCINOMA CLASSIFICATIONS The purpose of classifying neoplasias is to recognize groups with similar progress and prognosis and, if possible, receiving the same treatment. This is why those classifications are systematically being submitted to review and impro- vement through the new technologies. Differentiation of various entities in renal cancer has been comparatively fast, as the new genetic and molecular dis- coveries have confirmed the morphologic criteria of the different cell types, thus making it possible to open new thera- peutic pathways. Using the current WHO classification we recognize subtypes with excellent prognosis (Multilocular cystic renal carci- noma, Type I renal papillary carcinoma, Tubular and fusocellular mucinous carcinoma), other very aggressive ones (Bellini's collecting duct carcinoma, Medullary carcinoma), and also that the sarcomatoid transformation, even in small areas, impacts the prognosis negatively. Childhood-characteristic renal carcinomas associated with chromosome trans- locations have been recognized (genetic fusion TFE3 or TFEB), as well as the family forms of renal carcinoma. Regarding the UICC (International Union Against Cancer) classification, there are a series of aspects under argument (size, venous invasion, microvascular invasion, invasion of the adipous tissue of the renal sinus) that shall be discussed too, since it is possible that some modifications of the TNM might occur in the near future.Actas urologicas españolas 04/2006; 30(4). DOI:10.1016/S0210-4806(06)73461-1 · 1.15 Impact Factor
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ABSTRACT: The renal medulla comprises an intricate system of tubules, blood vessels and interstitium that is not well understood by most general pathologists. We conducted an extensive review of the literature on the renal medulla, in both normal and pathologic conditions. We set out in detail the points of key interest to pathologists: normal and pathological development, physiology, microscopic anatomy, histology and immunohistochemistry; and the specific and most common other types of disease associated with this part of the kidney: developmental abnormalities, (multicystic dysplastic kidney, autosomal dominant and recessive polycystic kidney diseases, medullary cystic kidney disease), inflammatory conditions (xanthogranulomatous pyelonephritis, malakoplakia), hyperplasia and dysplasia, and neoplastic processes (oncocytoma, atypical oncocytic tumors, chromophobe cell carcinoma, collecting duct carcinoma, urothelial carcinoma, other carcinomas, renal medullary fibroma and metastatic tumors). This condensed overview of the origin, function and pathology of the renal medulla, both in terms of development, inflammation and neoplastic processes, should help focus the interest of clinical pathologists on this widely overlooked part of the kidney.Pathology - Research and Practice 12/2014; 211(4). DOI:10.1016/j.prp.2014.12.009 · 1.56 Impact Factor