J Korean Med Sci.  2007 Feb;22(1):159-162. 10.3346/jkms.2007.22.1.159.

Mixed Epithelial and Stromal Tumor of the Kidney: A Case Report

• Kwon JE
• Kang JH
• Kwon GY

• KMID: 1713259
• DOI: http://doi.org/10.3346/jkms.2007.22.1.159

Abstract

The descriptive term "mixed epithelial and stromal tumor of the kidney" was recently proposed for a group of renal tumors characterized histologically by a mixture of stromal and epithelial proliferation. It is a rare benign neoplasm of the kidney which has been reported under various names such as adult type mesoblastic nephroma or others. We report a case of mixed epithelial and stromal tumor in a 47 yr old female patient presenting as a partly cystic and partly solid renal mass. Microscopically, the tumor exhibited spindle cell component in solid portion and epithelial proliferation around microcystic areas. Immunoreactive profiles and ultrastructural examination suggested myofibroblastic nature of the stromal cells. We believe this case exemplifies a unique adult renal tumor displaying both epithelial and stromal neoplastic component and has a few unusual features worthy of attention.

Keyword

Kidney; Nephroma, Mesoblastic; Adult

MeSH Terms

Nephroma, Mesoblastic/pathology
Neoplasms, Glandular and Epithelial/*pathology
Middle Aged
Kidney Neoplasms/*pathology
Humans
Female
Diagnosis, Differential

Figure

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  Fig. 1 Contrast-enhanced CT shows a well-enhancing solid component within the multiseptated cystic lesion arising from the right kidney (arrow). The lesion also has multifocal calcifications in the cystic wall.

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  Fig. 2 A largely cystic mass is found in the mid to lower pole of the kidney and contains an eccentric solid nodule.

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  Fig. 3 Grossly solid portion displays spindle cells in the fibrillar background (H&E, ×100). (Inset) The cells are reactive for smooth muscle actin (×100).

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  Fig. 4 Around the microcystic component, florid epithelial proliferation is found which assume papillary configuration with intervening foamy histiocytes (H&E, ×40). (Inset) The epithelial cells are positive for pancytokeratin (×100).

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  Fig. 5 Electron microscopic examination from solid area reveals spindle-shaped tumor cells showing many subplasmalemmal pinocytotic vesicles (arrow) and intracytoplasmic filaments occasionally forming dense bodies (×10,000).

Reference

1. Michal M, Syrucek M. Benign mixed epithelial and stromal tumor of the kidney. Pathol Res Pract. 1998. 194:445–448.

2. Adsay NV, Eble JN, Srigley JR, Jones EC, Grignon DJ. Mixed epithelial and stromal tumor of the kidney. Am J Surg Pathol. 2000. 24:958–970.

3. Durham JR, Bostwick DG, Farrow GM, Ohorodnik JM. Mesoblastic nephroma of adulthood. Report of three cases. Am J Surg Pathol. 1993. 17:1029–1038.

4. Truong LD, Williams R, Ngo T, Cawood C, Chevez-Barrios P, Awalt HL, Brown RW, Younes M, Ro JY. Adult mesoblastic nephroma: expansion of the morphologic spectrum and review of literature. Am J Surg Pathol. 1998. 22:827–839.

5. Trillo AA. Adult variant of congenital mesoblastic nephroma. Arch Pathol Lab Med. 1990. 114:533–535.

6. Daniel L, Lechevallier E, Bouvier C, Coulange C, Pellissier JF. Adult mesoblastic nephroma. Pathol Res Pract. 2000. 196:135–139.

7. Pawade J, Soosay GN, Delprado W, Parkinson MC, Rode J. Cystic hamartoma of the renal pelvis. Am J Surg Pathol. 1993. 17:1169–1175.

8. Aoyagi T, Kakudo K, Satoh S, Hata J, Shiramizu M, Tamaoki N. Multilocular cystic nephroma in an adult: immunohistochemical study. J Urol. 1987. 138:397–399.

9. Nagao T, Sugano I, Ishida Y, Tajima Y, Masai M, Nagakura K, Matsuzaki O, Kondo Y, Nagao K. Cystic partially differentiated nephroblastoma in an adult: an immunohistochemical, lectin histochemical and ultrastructural study. Histopathology. 1999. 35:65–73.

10. Lee HS, Jeong YY, Choi S, Kang HK. Calcified mesoblastic nephroma in an adult: a case report. J Korean Radiol Soc. 2002. 46:247–249.

11. Lim CS, Lee KH, Seong DH, Lee T, Yoon SM. A case of mesoblastic nephroma in adulthood. Korean J Nephrol. 2000. 19:1163–1167.

12. Koo JH, An HJ, Lee CK, Rhew HY. A case of mesoblastic nephroma of kidney in adult. Korean J Urol. 1999. 40:1566–1568.

13. Eble JN, Sauter G, Epstein JI, Seseterhehn IA, editors. World Health Organization Classification of Tumours. Tumors of the Urinary system and Male Genital Organs. 2004. Lyon: IARC Press.

14. Nakagawa T, Kanai Y, Fujimoto H, Kitamura H, Furukawa H, Maeda S, Oyama T, Takesaki T, Hasegawa T. Malignant mixed epithelial and stromal tumours of the kidney: a report of the first two cases with a fatal clinical outcome. Histopathology. 2004. 44:302–304.

15. Block NL, Grabstald HG, Melamed MR. Congenital mesoblastic nephroma (leiomyomatous hamartoma): first adult case. J Urol. 1973. 110:380–383.

16. Pierson CR, Schober MS, Wallis T, Sarkar FH, Sorensen PH, Eble JN, Srigley JR, Jones EC, Grignon DJ, Adsay V. Mixed epithelial and stromal tumor of the kidney lacks the genetic alterations of cellular congenital mesoblastic nephroma. Hum Pathol. 2001. 32:513–520.

17. Wang J, Arber DA, Frankel K, Weiss LM. Large solitary fibrous tumor of the kidney: report of two cases and review of the literature. Am J Surg Pathol. 2001. 25:1194–1199.

18. Stone CH, Lee MW, Amin MB, Yaziji H, Gown AM, Ro JY, Tetu B, Paraf F, Zarbo RJ. Renal angiomyolipoma: further immunophenotypic characterization of an expanding morphologic spectrum. Arch Pathol Lab Med. 2001. 125:751–758.

19. Delahunt B, Beckwith JB, Eble JN, Fraundorfer MR, Sutton TD, Trotter GE. Cystic embryonal sarcoma of kidney: a case report. Cancer. 1998. 82:2427–2433.

20. Hennigar RA, Beckwith JB. Nephrogenic adenofibroma. A novel kidney tumor of young people. Am J Surg Pathol. 1992. 16:325–334.