Small Cell Variant of Renal Oncocytoma – a Case Report of Unusual Histopathologic Entity

Vladimír Bartoš

Abstract


Renal oncocytoma (RO) accounts for 3–7% of all renal cells tumors. It typically consistes of large eosinophilic cells (oncocytes) with abundant cytoplasm, which constitute the crucial diagnostic feature. In 2001, the Czeck authors first described an unusual small cell variant of RO and untill now, only a few reports of such cases have been published. In the current article, the author presents an additional new case. 40-year old male with macroscopic hematuria as a clinical symptom was diagnosed to have solitary tumor in the upper third of the right kidney. He underwent a nephrectomy. On light microscopy, the tumor was predominantly composed of uniform small cells („oncoblasts“) with scant cytoplasm, hyperchromic nuclei and high nuclear-to-cytoplasmic ratio. In addition, it also contained characteristic oncocytes typical for oncocytoma. Tumor was strongly immunoreactive for EMA, sporadically positive for CK7 and negative for RCC antigen, vimentin, S100, WT1, chromogranin and synaptophysin. Proliferative activity did not exceed 1% and mitotic activity was virtually absent. No necrosis or aggressive growth features were found. The spectrum of histopathologic and immunohistochemical findings was consistent with a diagnosis of small cell variant of RO. The author focus on histopathological aspects and differential diagnostic pitfalls of this unique lesion.     


Keywords


renal oncocytoma; oncocytes; „oncoblasts“

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References


Michal M, Hes O, Mukenšnabl P. Tumors of the adult kidney [Nádory ledvin dospelého veku]. Plzen: Euroverlag s.r.o, 2000; 143. ISBN 80-7177-518-5

Fabišovský M, Fikoczek H, Dvorácková J, Krhut J. Renal oncocytoma and possibilities of its preoperative diagnostics [Renální onkocytom a možnosti jeho preoperacní diagnostiky]. Klin Urol. 2011;7(2-3):68-71.

Blaško M, Brutenic J, Hoffmann J, Trebatický B, Breza J. Výskyt a charakteristika onkocytómov oblicky. Klin Urol. 2006;2(3):146-150.

Amin MB, Crotty TB, Tickoo SK, Farrow G. Renal oncocytoma: a reappraisal of morphologic features with clinicopathologic findings in 80 cases. Am J Surg Pathol. 1997;21(1):1-12. DOI: https://doi.org/10.1097/00000478-199701000-00001 [PMid:8990136]

Perez-Ordonez B, Hamed G, Campbell S, et al. Renal oncocytoma: a clinicopathologic study of 70 cases. Am J Surg Pathol. 1997;31(8):871-883. DOI: https://doi.org/10.1097/00000478-199708000-00001

Kolníková G, Marinová P, Gál V, et al. Renal oncocytoma with invasive histopathologic features – case reports. Klin Onkol. 2014;27(2):138-142. DOI: https://doi.org/10.14735/amko2014137 [PMid:24739051]

Hes O, Michal M, Šulc M, et al. Kidney oncocytes - morphological variability of 102 cases [Onkocytom ledviny – morfologická variabilita 102 prípadu]. Ces-slov Patol. 2001;37(2):51-56.

Hes O, Michal M, Boudova L, Mukensnabl P, Kinkor Z, Miculka P. Small cell variant of renal oncocytoma - a rare and misleading type of benign renal tumor. Int J Surg Pathol. 2001;9(3):215-222. DOI: https://doi.org/10.1177/106689690100900307

Sokolova IA, Hes O, Michal M, Matsko DE. Small-cell variant of renal oncocytoma. Arkh Patol. 2007;69(5):34-36. [PMid:18074818]

Petersson F, Šíma R, Grossman P, et al. Renal small cell oncocytoma with pseudorosettes A histomorphologic, immunohistochemical, and molecular genetic study of 10 cases. Hum Pathol. 2011;42:1751-1760. DOI: https://doi.org/10.1016/j.humpath.2011.01.022

Kuroda N, Yorita K, Naroda T, Hayashi Y, Murakami I. Renal oncocytoma, small cell variant, with pseudorosettes, showing cyclin D1 expression and tubulovesicular cristae of mitochondria. Pathol Int. 2016;66(7):409-410. DOI: https://doi.org/10.1111/pin.12410

Zhang W, Yu W, Wang Q, Jiang Y, Li Y. The clinicopathological, ultrastructural, genetic features and diagnosis of small cell variant renal oncocytoma. Acta Histochem. 2015;117(6):505-511. DOI: https://doi.org/10.1016/j.acthis.2014.11.013

Jeung JA, Cao D, Selli BW, et al. Primary renal carcinoid tumors: clinicopathologic features of 9 cases with emphasis on novel immunohistochemical findings. Hum Pathol. 2011;42(10):1554-1561 DOI: https://doi.org/10.1016/j.humpath.2010.12.019

Mantoan Padilha M, Billis A, Allende D, Zhou M, Magi-Galluzzi C. Metanephric adenoma and solid variant of papillary renal cell carcinoma: common and distinctive features. Histopathology. 2013;62(6):941-953. DOI: https://doi.org/10.1111/his.12106

Celli R, Cai G. Ewing sarcoma/primitive neuroectodermal tumor of the kidney: a rare and lethal entity. Arch Pathol Lab Med. 2016;140(3):281-285. DOI: https://doi.org/10.5858/arpa.2014-0367-RS

Monaco SE, Teot LA. Cytopathology of pediatric malignancies: Where are we today with fine-needle aspiration biopsies in pediatric oncology? Cancer Cytopathology. 2014;122(5):322–336. DOI: https://doi.org/10.1002/cncy.21401

Truong LD, Shen SS. Immunohistochemical diagnosis of renal cell neoplasms. Arch Pathol Lab Med. 2011;135(1):92–109.




DOI: http://dx.doi.org/10.21802/gmj.2017.3.3

Copyright (c) 2017 Vladimír Bartoš

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