LGCmain
Indian Journal of Pathology and Microbiology
Home About us Instructions Submission Subscribe Advertise Contact e-Alerts Ahead Of Print Login 
Users Online: 749
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
IJPM is coming out with a Special issue on "Genitourinary & Gynecological pathology including Breast". Please submit your articles for these issues


 
CASE REPORT Table of Contents   
Year : 2009  |  Volume : 52  |  Issue : 3  |  Page : 389-391
Metanephric stromal tumor: A novel pediatric renal neoplasm


Department of Pathology and Pediatric Surgery, ICH and HSPL for Children (Madras Medical College), Chennai - 8, Tamil Nadu, India

Click here for correspondence address and email

Date of Web Publication12-Aug-2009
 

   Abstract 

Metanephric stromal tumor of kidney is a novel pediatric benign stromal specific renal neoplasm. A few cases have been reported in adults also. This tumor is usually centered in the renal medulla with a characteristic microscopic appearance which differentiates this lesion from congenital mesoblastic nephroma and clear cell sarcoma of the kidney. In most cases complete excision alone is curative. The differentiation of metanephric stromal tumor from clear cell sarcoma of the kidney will spare the child from the ill effects of adjuvant chemotherapy. In this communication we describe the gross and microscopic features of metanephric stromal tumor in a one-month-old child with good prognosis.

Keywords: Kidney, metanephric stromal tumor, pediatric neoplasm

How to cite this article:
Rajalakshmi V, Chandran P, Selvambigai, Ganesh J. Metanephric stromal tumor: A novel pediatric renal neoplasm. Indian J Pathol Microbiol 2009;52:389-91

How to cite this URL:
Rajalakshmi V, Chandran P, Selvambigai, Ganesh J. Metanephric stromal tumor: A novel pediatric renal neoplasm. Indian J Pathol Microbiol [serial online] 2009 [cited 2019 Dec 14];52:389-91. Available from: http://www.ijpmonline.org/text.asp?2009/52/3/389/55003



   Introduction Top


Stromal tumors of the kidney form 15% of the pediatric renal tumors. Metanephric stromal tumor (MST), a purely stromal specific renal neoplasm has a characteristic microscopic appearance that helps to differentiate between congenital mesoblastic nephroma (CMN) and clear cell sarcoma of kidney (CCSK). Complete excision is curative in most cases of MST. The differentiation of MST from clear cell sarcoma of the kidney is very important as it will spare the child from the adjuvant chemotherapy.


   Case Report Top


A one-month-old female child presented with abdominal swelling. Ultrasonogram revealed a solid and cystic mass in the left kidney. Intravenous voiding ureterogram of the right kidney was normal. No excretion was seen in left kidney. Diagnosis of Wilm's tumor of the left kidney was made and left nephrectomy was done. Histopathological sections from the nephrectomy specimen showed features of MST with immunohistochemistry (IHC) findings confirming the diagnosis.

Pathology

Gross: Nephrectomy specimen showed kidney measuring 6 x 4.4 cm. In one pole of the kidney a solid and cystic lesion of 3 x 3 cm centered in the renal medulla filled with necrotic material was seen. The wall of the cyst showed tiny papillary projections in a few foci with tan areas.

Microscopy under low power revealed renal parenchyma with a neoplasm having a nodular appearance and showing scalloped borders with renal parenchyma [Figure 1] and [Figure 2]. The neoplasm showed cystic areas [Figure 3].

There was perivascular and peritubular cuffing by the neoplastic cells forming collarettes with onionskin appearance [Figure 4]. The neoplastic cells were spindle-shaped with hyperchromatic nuclei. Blood vessels with tortuosity and hypertrophied media with epithelioid transformation of medial cells were seen [Figure 5]. No heterologous differentiation was seen.

IHC for CD 34 was positive focally and negative for Desmin.

Based on the microscopic appearance and IHC a diagnosis of MST was made.


   Discussion Top


MST is an under-reported pediatric pure stromal neoplasm of kidney with good prognosis. A few cases have been reported in adults also. MST along with metanephric adenofibroma and metanephric adenoma represent a spectrum of well-differentiated nephroblastic lesions that appear to be related to Wilm's tumor. [1] Argani and Beckwith [2] reported 31 cases of MST in their series with a benign course. In most cases complete excision alone is curative. The differentiation of MST from CCSK will spare the child from the toxic ill effects of adjuvant chemotherapy.

MST is usually a lesion centered in the renal medulla, but in one case continuous extension through the bladder to the prostatic urethra has been reported. [3] Microscopically, this neoplasm is an unencapsulated spindle to stellate cell lesion that entraps native kidney. Under low power it has a nodular appearance. Onion skin cuffing (collarettes) around tubules and blood vessels in myxoid background are also seen. These collarettes and angiodysplasia of intra tumoral vessels are the distinctive features of MST. Glia and cartilage-heterologous differentiation was seen in a few cases in the series of Argani and Beckwith. Our case did not show heterologous differentiation. Twelve of the 13 cases tested in the Argani and Beckwith series showed CD 34 positivity, and it was patchy in six of their cases as in our case. CD 34 positivity of MST differentiates it from CCSK. Desmin was negative in all these cases differentiating it from CMN. [4] Desmin was negative in our case also.

CCSK and CMN have to be differentiated from MST.

MST is differentiated from CCSK by the characteristic branching capillary vascular pattern seen in CCSK which is absent in MST. Nuclei in MST are thin and hyperchromatic and nuclei are ovoid and clear in CCSK. CD 34 can be a helpful differentiating feature because CCSKs are uniformly negative for this stain.

MST is differentiated from CMN by scalloped borders in contrast to the deeply invasive nature of CMN.

Nodular low power pattern of MST is in contrast to the sharply defined linear transitions. Heterologous differentiation and vascular changes are specific to MST though cartilage is occasionally seen in CMN. Desmin is negative in MST and it is positive in CMN. Desmin was negative in our case also.

All the MSTs behaved clinically in a benign fashion hence it is important to differentiate MST from aggressive mimics as excision or nephrectomy alone seems to be curative.

In conclusion, this communication highlights a case of MST, an under-reported pediatric renal neoplasm with good prognosis after total excision.


   Acknowledgement Top


We thank Miss. Preeti Pathanjali, for her secretarial services in the preparation of the manuscript and Dr. Priyadarshini, Post Graduate.

 
   References Top

1.Argani P, Beckwith JB, Renal neoplasms of childhood. In: Stacy. E Mills, editor. Sternberg's Diagnostic surgical pathology. 4 th ed. Lippincot Williams and Wilkins: Philadelphia; 2004. p. 2029-30.  Back to cited text no. 1    
2.Argani P, Beckwith JB. Metanephric stromal tumor: Report of 31 cases of a distinctive pediatric renal neoplasm. Am J Surg Pathol 2000;24:917- 26.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]
3.Lorenzo AJ, Timmons C, Weinberg A, Megison SM, Snodgrass WT. Metanephric stromal tumor with urothelial extension. J Urol 2003;169:1095- 7.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]
4.Nadasdy T, Roth J, Johnson DL, Bane BL, Weinberg A, Verani R, et al . Congenital Mesoblastic nephroma an immunohistochemical and lectin study. Hum Pathol 1993;24:413-9.  Back to cited text no. 4  [PUBMED]  

Top
Correspondence Address:
V Rajalakshmi
22/2, Murrays gate road, Alwarpet, Chennai, Tamil Nadu - 600 018
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0377-4929.55003

Rights and Permissions


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]

This article has been cited by
1 Metanephric stromal tumor with a rare incidence of squamous epithelium: A case report and a brief review of the literature
Jia Wang,Wenjie Jin,Xiangru Wu
Pathology - Research and Practice. 2017; 213(7): 863
[Pubmed] | [DOI]
2 Metanephric stromal tumour: A rare pediatric benign stromal specific renal neoplasm
SeemaD Khutti,RamaniP Kumar,Karl Sampath
Indian Journal of Urology. 2013; 29(1): 53
[Pubmed] | [DOI]
3 Recurrent Metanephric Stromal Tumor in an Infant
Maria Debora De Pasquale, Francesca Diomedi-Camassei, Annalisa Serra, Renata Boldrini, Alessandro Inserra, Paolo Caione, Alessandro Jenkner
Urology. 2011;
[VIEW] | [DOI]
4 Metanephric stromal tumor: a challenging diagnostic entity in children
Ayper Kacar, Müjdem Nur Azili, Birsen Songül Cihan, Haci Ahmet Demir, Hüseyin Tugrul Tiryaki, Pedram Argani
Journal of Pediatric Surgery. 2011; 46(12): e7
[VIEW] | [DOI]



 

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


    Abstract
    Introduction
    Case Report
    Discussion
    Acknowledgement
    References
    Article Figures

 Article Access Statistics
    Viewed3434    
    Printed115    
    Emailed0    
    PDF Downloaded217    
    Comments [Add]    
    Cited by others 4    

Recommend this journal