Low-Grade Clear Cell Renal Cell Carcinoma Mimicking Hemangioma of the Kidney A Series of 4 Cases
ABSTRACT Context.- Clear cell renal cell carcinoma (CCRCC) has a rich, sinusoid-like vascularity frequently used as a diagnostic criterion. CCRCC with predominantly vascular architecture has not been described. Objective.- To describe 4 unusual CCRCC cases, primarily presenting with hemangioma-like morphologic pattern. Design.- Clinicopathologic and selected immunohistochemical analysis of 4 cases of CCRCC mimicking hemangioma. Results.- Cases were seen in 1 woman and 3 men (average age, 48.8 years; range, 40-66 years). Grossly, tumors were red-brown (3 of 4) with scant bright-yellow foci in 1. The average tumor size was 4 cm (range, 2.5-5.5 cm). Microscopically, all were composed of varying proportions of a rich, arborizing, sinusoid-like vasculature with focal hobnail appearance of endothelial cells. Entrapment of renal tubules between blood vessels was seen at the periphery of the tumors. This morphology was reminiscent of anastomosing hemangioma. Isolated tumor cells resembling lymphocytes with clear halos were sparsely interspersed between vessels. Cytokeratin immunostain confirmed the diagnosis of CCRCC. Conclusion.- Extensive sampling and immunohistochemical workup of what is deemed to be a benign vascular neoplasm of the kidney is needed to rule out the presence of individual carcinoma cells or small viable carcinoma cell clusters.
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ABSTRACT: Context .- Eosinophilic renal neoplasms include a spectrum of solid and papillary tumors ranging from indolent benign oncocytoma to highly aggressive malignancies. Recognition of the correct nature of the tumor, especially in biopsy specimens, is paramount for patient management. Objective .- To review the diagnostic approach to eosinophilic renal neoplasms with light microscopy and ancillary techniques. Data Sources .- Review of the published literature and personal experience. Conclusions .- The following tumors are in the differential diagnosis of oncocytic renal cell neoplasm: oncocytoma, chromophobe renal cell carcinoma (RCC), hybrid tumor, tubulocystic carcinoma, papillary RCC, clear cell RCC with predominant eosinophilic cell morphology, follicular thyroid-like RCC, hereditary leiomyomatosis-associated RCC, acquired cystic disease-associated RCC, rhabdoid RCC, microphthalmia transcription factor translocation RCC, epithelioid angiomyolipoma, and unclassified RCC. In low-grade nonpapillary eosinophilic neoplasms, distinction between oncocytoma and low-grade RCC mostly rests on histomorphology; however, cytokeratin 7 immunostain may be helpful. In high-grade nonpapillary lesions, there is more of a role for ancillary techniques, including immunohistochemistry for cytokeratin 7, CA9, CD10, racemase, HMB45, and Melan-A. In papillary eosinophilic neoplasms, it is important to distinguish sporadic type 2 papillary RCC from microphthalmia transcription factor translocation and hereditary leiomyomatosis-associated RCC. Histologic and cytologic features along with immunohistochemistry and fluorescence in situ hybridization tests for TFE3 (Xp11.2) and TFEB [t(6;11)] are reliable confirmatory tests. Eosinophilic epithelial neoplasms with architecture, cytology, and/or immunoprofile not qualifying for either of the established types of RCC should be classified as unclassified eosinophilic RCC and arbitrarily assigned a grade (low or high).Archives of pathology & laboratory medicine 11/2014; 138(11):1531-41. DOI:10.5858/arpa.2013-0653-RA · 2.88 Impact Factor
Article: Mesenchymal tumors of adult kidney[Show abstract] [Hide abstract]
ABSTRACT: Mesenchymal tumors of the kidney, although infrequently encountered, constitute a wide spectrum of lesions. The relative rarity of these tumors means that in some instances criteria to differentiate between benign and malignancy are currently incompletely defined. More recently a variety of novel stromal tumors have been characterized, with hemangioblastoma and myopericytoma being notable examples. The identification of a subset of spindle cell tumors as synovial sarcoma, on the basis of the presence of a characteristic genetic translocation, has facilitated the correct classification of a number of tumors previously labeled as fibrosarcoma, malignant fibrous histiocytoma, or more recently cystic embryonal sarcoma. In this review, we have detailed the spectrum of both benign and malignant stromal tumors of the adult kidney, described the gross and microscopic features, with an emphasis on immunoexpression and the differential diagnosis of each tumor type. Copyright © 2015 Elsevier Inc. All rights reserved.Seminars in Diagnostic Pathology 02/2015; 32(2). DOI:10.1053/j.semdp.2015.02.007 · 1.80 Impact Factor
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ABSTRACT: Reported herein is a renal anastomosing hemangioma which developed slowly in the past four years. A 25-year-old woman was found a mass localized in the upper portion four years ago, and only slow progression in the past four years. She underwent a laparoscopic partial nephrectomy of right kidney and diagnosed as anastomosing hemangioma. On histology the vascular components of the tumor had an anastomosing pattern without well-definite margins. Immunohistochemically, only endothelial markers (CD31, CD34) were expressed on the vascular components of tumor cells. Smooth muscle actin (SMA), cytokeratin (CK), EMA and S-100 and so on were all negative in the epithelioid tumor cells. The patient was alive at 16 months after operation, without any evidence recurrence or metastasis. Anastomosing hemangioma is an extremely rare vascular neoplasm; only 23 cases were previously described until now. Our report of anastomosing hemangioma arising from the kidney with slow progression will improve the knowledge of primary vascular tumors arising in the kidney.International journal of clinical and experimental pathology 01/2015; 8(2):2208-13. · 1.78 Impact Factor