Korean J Urol.  2006 Nov;47(11):1133-1138. 10.4111/kju.2006.47.11.1133.

The Frequency of Perirenal Fat Invasion according to Size and Protrusion Shape of Renal Cell Carcinomas

• Lee HN
• Choi HY
• Lee TY

• KMID: 2294268
• DOI: http://doi.org/10.4111/kju.2006.47.11.1133

Abstract

Purpose
The perirenal fat surrounding a renal cell carcinoma (RCC) must be preserved during a surgical operation. However, the perirenal fat is often injured during an operation. In such cases, there is the possibility of cancer metastasis. The frequency of perirenal fat invasion and pathological features, according to the size and protrusion shape of RCCs were investigated. Materials and Methods: A retrospective reviewed 93 consecutive RCCs, resected at our institution, between January 1995 and June 2005, was conducted. The frequency of perirenal fat invasion, the pathologic T stage and nuclear grade, according to the size and protrusion shape of RCCs after a radical nephrectomy were also investigated. Eighty three out of 93 lesions were sub classified based on the percentage of the tumor extending from the normal parenchymal border; endophytic-less than 40%, mesophytic-40 to 60% and exophytic-greater than 60%. Results: Of the 93 lesions, 15 (16.1%) had perirenal fat invasion. Of the 38 lesions equal or smaller than 4cm, 2 (5.3%) had perirenal fat invasion, 4 (10.5%) a high T stage and 11 (28.9%) a high nuclear grade. Of the 33 lesions larger than 4cm, but equal or smaller than 7cm, 4 (12.1%) had perirenal fat invasion, 4 (12.1%) a high T stage and 12 (36.4%) a high nuclear grade. Of the 22 lesions larger than 7cm, 9 (40.9%) had perirenal fat invasion, 12 (54.5%) a high T stage and 17 (77.3%) a high nuclear grade. There were statistical differences in perirenal fat invasion, T stage and nuclear grade between lesions equal or smaller than 7cm and those larger than 7cm. The frequencies of perirenal fat invasion for endophytic, mesophytic and exophytic tumors were 12.2, 21.1 and 13.3% (6/49, 4/19 and 2/15), respectively, but there were no statistical differences in the percentages of perirenal fat invasion. The 5-year survival rates for patients without and with perirenal fat invasion were 91.9 and 72.7%, respectively (p=0.039). Conclusions: RCCs with a size of 4cm or smaller have a tendency for low perirenal fat invasion, but 5.3% of small RCCs had perirenal fat invasion. Therefore, an effort should be made to prevent possible metastasis by cautiously preserving the perirenal fat surrounding a renal mass during nephron sparing or minimally invasive surgery.

Keyword

Renal cell carcinoma; Nephrectomy; Metastasis

MeSH Terms

Carcinoma, Renal Cell*
Humans
Neoplasm Metastasis
Nephrectomy
Nephrons
Retrospective Studies
Surgical Procedures, Minimally Invasive
Survival Rate

Figure

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  Fig. 1 Survival curves according to the presence of perirenal fat invasion surrounding renal cell carcinomas (p=0.039).

Reference

1. Chow WH, Devesa SS, Warren JL, Fraumeni JF Jr. Rising incidence of renal cell carcinoma in the United States. JAMA. 1999. 281:1628–1631.

2. Jayson M, Sanders H. Increased incidence of serendipitously discovered renal cell carcinoma. Urology. 1998. 51:203–205.

3. Joniau S, Vander Eeckt K, Van Poppel H. The indications for partial nephrectomy in the treatment of renal cell carcinoma. Nat Clin Pract Urol. 2006. 3:198–205.

4. Tomita Y. Early renal cell cancer. Int J Clin Oncol. 2006. 11:22–27.

5. Gill IS, Desai MM, Kaouk JH, Meraney AM, Murphy DP, Sung GT, et al. Laparoscopic partial nephrectomy for renal tumor: duplicating open surgical techniques. J Urol. 2002. 167:469–476.

6. Greene FL, Page DL, Fleming ID. AJCC cancer staging manual. 2002. 6th ed. New York: Springer-Verlag;323–328.

7. Finley DS, Lee DI, Eichel L, Uribe CA, McDougall EM, Clayman RV, et al. Fibrin glue-oxidized cellulose sandwich for laparoscopic wedge resection of small lesions. J Urol. 2005. 173:1477–1481.

8. Fuhrman SA, Lasky LC, Limas C. Prognostic significance of morphologic parameters in renal cell carcinoma. Am J Surg Pathol. 1982. 6:655–663.

9. Nam JK, Cha CS, Chung MK. The treatment outcomes of a partial nephrectomy in the management of renal cell carcinomas. Korean J Urol. 2004. 45:1100–1105.

10. Flank I, Zincke H, Wehle M, Young P, Igel T, Petrou S, et al. The natural history of small solid renal tumors: revisiting the concept of non-surgical management. J Urol. 2001. 16:Suppl. 162. abstract 663.

11. Rendon RA, Stanietzky N, Panzarella T, Robinette M, Klotz LH, Thurston W, et al. The natural history of small renal masses. J Urol. 2000. 164:1143–1147.

12. Flank I, Blute ML, Cheville JC, Lohse CM, Weaver AL, Zincke H. Solid renal tumors: an analysis of pathological features related to tumor size. J Urol. 2003. 170:2217–2220.

13. Hsu RM, Chan DY, Siegelman SS. Small renal cell carcinoma: correlation of size with tumor stage, nuclear grade, ana histologic subtype. AJR Am J Roentgenol. 2004. 182:551–557.

14. Lee CT, Katz J, Shi W, Thaler HT, Reuter VE, Russo P. Surgical management of renal tumors 4cm or less in a contemporary cohort. J Urol. 2000. 163:730–736.

15. Fergany AF, Hafez KS, Novick AC. Long-term results of nephron sparing surgery for localized renal cell carcinoma: 10-year followup. J Urol. 2000. 163:442–445.

16. Kim DS, Woo YN, Lee TY. The value of tumor size as a prognostic factor in patients with localized renal cell carcinoma. Korean J Urol. 2002. 43:813–817.

17. Medeiros LJ, Gelb AB, Weiss LM. Renal cell carcinoma. Prognostic significance of morphologic parameters in 121 cases. Cancer. 1988. 61:1639–1651.

18. Jeong IG, Jeong CW, Hong SK, Kwak C, Lee ES, Lee SE. Prognostic implication of capsular invasion without perinephric fat infiltration in localized renal cell carcinoma. Urology. 2006. 67:709–712.

19. Han WK, Byun YJ, Lee YS, Kim YS, Rha KH, Hong SJ, et al. Perirenal fat invasion (pT3a) in renal cell carcinoma less than 4cm in size (cT1a): analysis of the prognostic and pathological implications. Korean J Urol. 2006. 47:596–600.