Table of Contents  
CASE REPORT
Year : 2014  |  Volume : 7  |  Issue : 5  |  Page : 675-678  

Endophytic renal cell carcinoma mimicking urothelial neoplasm of the pelvicalyceal system: A prime surgical concern


Department of Urology, Regional Institute of Medical Sciences (RIMS), Imphal, Manipur, India

Date of Web Publication10-Sep-2014

Correspondence Address:
Bijit Lodh
Department of Urology, Regional Institute of Medical Sciences, Lamphelpat, Imphal, Manipur - 795 004
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0975-2870.140496

Rights and Permissions
  Abstract 

Centrally infiltrating renal mass poses great diagnostic and therapeutic challenge for both radiologist and urologist. It is often practically impossible to dedifferentiate on imaging and will render patients to receive unnecessary aggressive surgery. Here we have presented such case for its utmost importance in the clinical settings and reviewed with the available literature. A 70-year-old female was preoperatively diagnosed having right intrarenal transition cell carcinoma, stage T 3 N 0 M 0 . Accordingly, she underwent right nephroureterectomy and the specimen was sent for histopathological examination that revealed an eosinophilic variant of chromophobe renal cell carcinoma (EVCRCC). Biologically it is a tumor of low malignant potential and therefore, in spite of nephroureterectomy, only nephrectomy or a more minimally invasive procedure is the ideal treatment. Henceforth, caution must be exercised while treating such entity and in uncertainty, we may consider a quick pre-operative image-guided percutaneous renal biopsy.

Keywords: Centrally infiltrating renal mass, endophytic renal cell carcinoma, intrarenal transitional cell carcinoma


How to cite this article:
Lodh B, Singh KA, Khumukcham S, Sinam RS. Endophytic renal cell carcinoma mimicking urothelial neoplasm of the pelvicalyceal system: A prime surgical concern. Med J DY Patil Univ 2014;7:675-8

How to cite this URL:
Lodh B, Singh KA, Khumukcham S, Sinam RS. Endophytic renal cell carcinoma mimicking urothelial neoplasm of the pelvicalyceal system: A prime surgical concern. Med J DY Patil Univ [serial online] 2014 [cited 2024 Mar 29];7:675-8. Available from: https://journals.lww.com/mjdy/pages/default.aspx/text.asp?2014/7/5/675/140496


  Introduction Top


Renal cell carcinoma (RCC) is the most lethal of the common urologic malignancies and accounts for 2-3% of all adult malignant neoplasms. Despite a resurgent interest in renal mass biopsy, a dedicated (thin-slice) CT scan remains the single most important radiographic test for delineating the nature of a renal mass. [1] However, centrally infiltrating renal tumors are the exception. The differential diagnosis of this entity includes intrarenal or infiltrating TCC, central or endophytic RCC, squamous cell carcinoma, renal medullary carcinoma, collecting duct carcinoma, renal lymphoma and few renal metastases. The diagnostic differentiation of endophytic RCC from intrarenal TCC on radiography is challenging and often indistinguishable. [2] But, the distinction has significant implication for treatment, because the former is usually managed with nephrectomy or with more minimally invasive procedures, whereas the latter requires radical nephroureterectomy and often wider lymphadenectomy. Nevertheless, the follow-up strategies also differ significantly. [3],[4] Here, we have discussed a case of endophytic RCC that managed aggressively because of its radiologic mimic as intrarenal TCC on pre-operative evaluation.


  Case Report Top


A 70-year-old female presented to the Urology out-patient department with complaints of dull aching right flank pain and hematuria on and off for last 12 months. Except chronic beedi smoking for last 25 years, she had no other significant past and family history. On examination she was pale and no abdominal lump was palpable. Laboratory investigation showed hemoglobin 9.4 gm%, TLC count 6300/mm 3 , serum creatinine 0.8 mg%, urine pus cell 6-8/hpf with culture positive for E. coli. Urine cytology was negative for malignant cells. Ultrasound KUB showed homogeneously echogenic lesion within the pelvicalyceal system (PCS) of the right kidney with separation of the renal sinus fat and grade-II HDN [Figure 1]. Contrast-enhanced computed tomography revealed an infiltrating homogeneously enhancing lesion (approximately 3.59 × 2.82 × 1.71 cm) with its center located in the upper pole collecting system and extension toward the right renal pelvis without any distortion of the renal shape [Figure 2],[Figure 3],[Figure 4],[Figure 5] and [Figure 6]. There was no evidence of renal vein thrombus and the opposite kidney was excreting normally. Based on the imaging, a provisional diagnosis of intrarenal TCC with stage T 3 N 0 M 0 was made. Per-operatively, a retrograde ureteropyelogram was also performed that revealed filling defect of the right PCS. Accordingly, an open radical nephroureterectomy was executed and specimen sent for histopathological examination. On gross examination, the nephrectomized kidney measured 10 × 5 × 2.5 cm without any apparent nodular bulge. On cut section, a well circumscribed yellowish brown solid mass arising at the corticomedullary junction with infiltration of the renal sinus fat and stretching of the overlying PCS was noticed [Figure 7]. Light microscopy showed small to medium sized cells with abundant granular eosinophilic cytoplasm arranged in trabeculae and nests. There was also evidence of mild-to-moderate nuclear pleomorphism with peri-nuclear halo, suggestive of eosinophilic variant of Chromophobe RCC [Figure 8]. Hale's colloidal iron stain showed a diffuse reticular staining pattern [Figure 9]. However, the sections of the renal artery, renal vein, perinephric fat and proximal and distal ends of ureter showed no evidence of tumor invasion.
Figure 1: Ultrasound KUB (Yellow arrow — homogeneously hyperechoic mass located centrally within the collecting system of the right kidney with separation of the echogenic renal sinus fat; Black arrow — grade-II HDN)

Click here to view
Figure 2: Non-contrast computed tomography, axial section (Black arrow — well-defined isodense lesion with its center located in the upper pole collecting system of the right kidney)

Click here to view
Figure 3: Contrast-enhanced computed tomography, axial section nephrographic-phase (Black arrow — Infiltrative and homogeneously enhancing lesion with its center located in the upper pole collecting system; Yellow arrow — mass extends within the renal pelvis)

Click here to view
Figure 4: Contrast-enhanced computed tomography, axial section excretory-phase (Black arrow — fi lling defect within the right renal pelvis)

Click here to view
Figure 5: Contrast-enhanced computed tomography, coronal section nephrographic-phase (Black arrow — homogeneously enhancing lesion occupying the upper pole collecting system with extension into renal pelvis)

Click here to view
Figure 6: Contrast-enhanced computed tomography, sagittal section nephrographic-phase (Black arrow — Infiltrating and homogeneously enhancing mass within the upper pole collecting system)

Click here to view
Figure 7: Gross specimen of the nephrectomized right kidney (Black arrow — well circumscribed yellowish brown solid mass arising at the corticomedullary junction with infiltration of the renal sinus fat and stretching of the overlying pelvicalyceal system)

Click here to view
Figure 8: Photomicrograph of EVCRCC on light microscopy (Black arrow — small to medium sized cells with abundant granular eosinophilic cytoplasm arranged in trabeculae and nests; Yellow arrow — mild to moderate nuclear pleomorphism with peri-nuclear halo)

Click here to view
Figure 9: Photomicrograph of EVERCC on Hale's colloidal iron stain, showing a diffuse reticular staining pattern

Click here to view



  Discussion Top


In this modern era, surgeon are blessed with sophisticated imaging for making the therapeutic decision, and in majority the radiologic findings corroborate with histopathology. However, in certain circumstances a thoughtful proceeding is necessary and one of such is centrally infiltrating renal masses. A broad pathologic spectrum of tumors falls in the differential diagnosis of this entity and among these centrally located RCC and intrarenal TCC most often presents as a radiologic dilemma because of their relative frequency. There is strong evidence that endophytically growing RCC frequently mimics as urothelial neoplasm of the PCS on radiology. [5],[6] Raza et al. [2] established 15 useful CT features for differentiating intrarenal TCC from centrally located RCC and are summarized briefly. According to them, individual parameters most predictive of intrarenal TCC were tumor centered within the collecting system, a filling defect in the renal pelvis, preservation of reniform contour, absence of cystic or necrotic change, homogeneous tumor enhancement and tumor extension toward the ureteropelvic junction. Other factors include absence of calcification, pelvicalyceal invasion, urothelial thickening, oncocalyx, focally obstructed calyx, hydronephrosis, ureteric infiltration, absence of renal vein invasion, absence of perinephric changes. Although, the present case was strongly in favor of a particular diagnosis, it remained enigmatic and pre-operative imaging did not correlate with the histology findings. In our case, the histopathology was suggestive of eosinophilic variant of Chromophobe RCC (EVCRCC). The Chromophobe renal cell carcinoma (ChRCC) is an uncommon variant that accounts for 4-11% of all RCC. Aggregate literature suggests that biologically it is a tumor of low malignant potential with reported 5-year and 10-year survival rates of 78% to 100% and 80% to 90%, respectively. [7] Several previous studies and reviews have described similar imaging characteristics for centrally located RCC. Muqiya et al., [8] in their study found that ChRCC generally exhibit a homogeneously hyperechoic lesion on ultrasound. Prando et al. [9] demonstrated that endophytically growing RCC presents with a preserved renal shape. Heterogeneous or predominantly peripheral enhancement was frequent in conventional (84%), papillary (74%) and collecting duct (100%) renal carcinomas, whereas homogeneous enhancement was commonly noted in ChRCC (69%). [10] Considering the fact that imaging is challenging, adoption of an additional procedure like percutaneous renal biopsy (PRB) may be more appropriate in aiding further diagnosis. Historically renal tumor biopsy has selective indications. However, with the modern image guidance, improved biopsy techniques, increasing expertise of urologists, interventional radiologists and pathologists, the current indications for renal tumor biopsies have expanded. The procedure is associated with low morbidity, no virtual risk of seeding and having a good diagnostic yield for malignancy It is indicated in the diagnostic work-up of renal tumors that are indeterminate on imaging and of incidentally detected, radiologically suspicious SRMs (<4 cm) in patients at high surgical risk to support treatment decisions and avoid unnecessary surgery. [11] In the present study, we were biased by the imaging and executed a more aggressive surgery that could have been avoided.


  Conclusion Top


The present case illustrates that caution should be exercised in diagnosis of a centrally infiltrating renal tumor. Renal cell carcinoma must be considered in the differential diagnosis of such entity. In uncertain cases, a quick pre-operative image-guided percutaneous renal biopsy and histopathologic examination is recommended after weighing the risk-benefit ratio.

 
  References Top

1.Campbell SC, Lane BR. Malignant renal tumors. In: Wein AJ, editor. Campbell-Wash Urology, 10 th ed. United States: Elsevier Saunders; 2010. p. 1416-9.  Back to cited text no. 1
    
2.Raza SA, Sohaib SA, Sahdev A, Bharwani N, Heenan S, Verma H, et al. Centrally infiltrating renal masses on CT: Differentiating intrarenal transitional cell carcinoma from centrally located renal cell carcinoma. AJR Am J Roentgenol 2012;198:846-53.  Back to cited text no. 2
    
3.Rathmell WK, Godley PA. Recent updates in renal cell carcinoma. Curr Opin Oncol 2010;22:250-6.  Back to cited text no. 3
    
4.Remzi M, Shariat S, Huebner W, Fajkovic H, Seitz C. Upper urinary tract urothelial carcinoma: What have we learned in the last 4 years? Ther Adv Urol 2011;3:69-80.   Back to cited text no. 4
    
5.Kim SH, Sim JS. Malignant renal parenchymal tumors. In: Kim SH, editor. Radiology illustrated: Uroradiology, 2 nd ed. New York: Springer; 2011. p. 156.  Back to cited text no. 5
    
6.Holalkere NS, Hayashi D, Guermazi A. Renal cell carcinoma. In: Quaia E, editor. Radiological imaging of the kidney, kindle edition. New York: Springer; 2010. p. 553.   Back to cited text no. 6
    
7.Amin MB, Paner GP, Alvarado CI, Young AN, Stricker HJ, Lyles RH, et al. Chromophobe renal cell carcinoma: Histomorphologic characteristics and evaluation of conventional pathologic prognostic parameters in 145 cases. Am J Surg Pathol 2008;32:1822-34.  Back to cited text no. 7
    
8.Muqiya S, Nagata M, Ozono S, Ito T, Maruyama S, Hadano S, et al. Ultrasonographic features of Chromophobe cell renal carcinoma. Hinyokika Kiyo 2004;50:865-8.  Back to cited text no. 8
    
9.Prando A, Prando P, Prando D. Urothelial cancer of the renal pelvicaliceal system: Unusual imaging manifestations. Radiographics 2010;30:1553-66.  Back to cited text no. 9
    
10.Kim JK, Kim TK, Ahn HJ, Kim CS, Kim KR, Cho KS. Differentiation of subtypes of renal cell carcinoma on helical CT scans. AJR Am J Roentgenol 2002;178:1499-506.   Back to cited text no. 10
    
11.Volpe A, Finelli A, Gill IS, Jewett MA, Martignoni G, Polascik TJ, et al. Rationale for percutaneous biopsy and histologic characterisation of renal tumours. Eur Urol 2012;62:49-68.  Back to cited text no. 11
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]



 

Top
   
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Case Report
Discussion
Conclusion
References
Article Figures

 Article Access Statistics
    Viewed3987    
    Printed125    
    Emailed1    
    PDF Downloaded223    
    Comments [Add]    

Recommend this journal