Indian Journal of Pathology and Microbiology

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Year
: 2018  |  Volume : 61  |  Issue : 4  |  Page : 620--622

MiT family translocation-associated (TFE3 positive) renal cell carcinoma of childhood


Richa Katiyar1, Shashikant C U. Patne1, Sarita Chowdhary2,  
1 Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
2 Department of Paediatric Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India

Correspondence Address:
Shashikant C U. Patne
Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi - 221 005, Uttar Pradesh
India




How to cite this article:
Katiyar R, U. Patne SC, Chowdhary S. MiT family translocation-associated (TFE3 positive) renal cell carcinoma of childhood.Indian J Pathol Microbiol 2018;61:620-622


How to cite this URL:
Katiyar R, U. Patne SC, Chowdhary S. MiT family translocation-associated (TFE3 positive) renal cell carcinoma of childhood. Indian J Pathol Microbiol [serial online] 2018 [cited 2019 Nov 22 ];61:620-622
Available from: http://www.ijpmonline.org/text.asp?2018/61/4/620/242970


Full Text



 Introduction



Translocation-associated renal cell carcinoma (t-RCC) is a group of uncommon tumors, which are characterized by recurrent gene rearrangements of TFE3 and transcription factor EB (TFEB) loci and have two distinct subtypes, namely, Xp11- and t(6;11) t-RCC, respectively.[1] Both TFE3 and TFEB loci belong to microphthalmia transcription factor (MiT) family, therefore, in the recent 2016 classification of the World Health Organization, these tumors are now categorized as MiT family translocation-associated RCC (MiT-RCC).[2] Out of these two types of t-RCC, Xp11 t-RCC involve TFE3 gene, which commonly fuses to PRCC and ASPL loci on chromosomes 1q21 and 17q25, respectively.[1] These fusions produce overexpression of TFE3 protein, which can be immunohistochemically demonstrated in the nuclei of tumor cells.[3] We herein report a case of TFE3-positive Xp11 t-RCC in a child.

 Case Report



A 12-year-old boy presented with 4 days' history of abdominal pain and reddish discoloration of urine. Ultrasound examination of the abdomen showed 35 cm × 32 mm size complex mixed echogenic mass in the renal pelvis and lower pole calyx of the right kidney. Contrast-enhanced computed tomography (CT) scan of the abdomen with three-dimensional reconstruction revealed ill-defined homogenously enhancing lesion of size 35 mm × 50 mm × 24 mm in renal pelvis, upper ureter and lower pole calyx of the right kidney with nonvisualization of the right ureter [Figure 1]. Adjacent fat planes were well maintained with dilatation of pelvicalyceal system. Hyperdense blood clot was noted in dilated calyces. Radiological features were in favor of neoplastic lesion (Wilms tumor vs. renal cell carcinoma). Except for the presence of red cells on urinalysis, patient's other routine preoperative laboratory tests were within the normal limits. He underwent right radical nephrectomy, and specimen was submitted for histopathological examination. Specimen of right kidney measured 10 cm × 5 cm × 3.5 cm with right ureter of length 7 cm. Cut section revealed a tumor in lower pole measuring 3 cm × 2 cm × 2 cm, arising from medullary area and reaching up to pelviureteric junction [Figure 2]. Renal calyces were filled with blood clot and mucoid material. Microscopic examination showed a tumor arranged in acini and papillae with slender fibrovascular septae containing lymphocytic infiltrate and focal psammomatous calcification [Figure 3]a, [Figure 3]b. The tumor cells were polygonal with abundant clear to granular cytoplasm; centrally placed larger pleomorphic nuclei with prominent nucleoli [Figure 3]c. Reticulin stain accentuated papillary and acinar architecture. Immunohistochemical study using standard procedure showed tumor cells positive for TFE3 [Figure 3]d, focally positive for vimentin while negative for pancytokeratin, CK7, CD10, and HMB-45. A final diagnosis of TFE3-positive Xp11 t-RCC was made.{Figure 1}{Figure 2}{Figure 3}

 Discussion



Xp11 t-RCC is an uncommon tumor that comprises 40% of the pediatric RCC and 5% of the adult RCC.[1] Previous exposure to chemotherapy with DNA topoisomerase II inhibitors or alkylating agents is known risk factor.[1] However, history of prior chemotherapy was not present in our patient. Among children and young adults under 45 years of age, Xp11 t-RCC with TFE3 gene mutation is common with male:female ratio of 1:2.5.[3],[4] Rarely, t-RCC show t(6;11) involving TFEB gene. These fusions result in overexpression of TFE3 protein and TFEB protein, respectively which can be detected immunohistochemically by demonstrating nuclear staining. TFE3 break-apart fluorescence in situ hybridization probe is the most sensitive and specific method to diagnose Xp11 t-RCC.[3] Grossly, these tumors often resemble clear cell RCC by showing tan yellow cut surface with areas of hemorrhage and necrosis. Microscopically, these tumors are characterized by clear and eosinophilic tumor cells having large pleomorphic nuclei with vesicular chromatin, prominent nucleoli, and discrete cell borders exhibiting characteristic papillary and nested pattern of growth with psammoma bodies and intracytoplasmic hyaline droplets.[5] Microscopically, t-RCC is difficult to differentiate from papillary and clear cell containing lesions of the kidney, i.e., clear cell RCC, Type I papillary RCC and a recently recognized entity in the WHO 2016 classification-clear cell papillary RCC.[3] Key differentiating features among these entities is given in [Table 1].[1],[2] In addition, rare differential diagnosis of Xp11 t-RCC includes recently identified TCEB1-mutated RCC, which shows tubular and papillary architecture of medium-sized clear cells with thick intervening fibromuscular stromal bands. TCEB1-mutated RCC, in contrast to Xp11 t-RCC, show diffuse immunostaining for carbonic anhydrase-IX, immunopositivity for epithelial markers, negative staining for melanocytic markers, and absence of TFE3 or TFEB gene rearrangements.[1] The most common treatment option for Xp11 t-RCC is radical nephrectomy; however, nephron-sparing surgery has also been successfully used for small-sized (<7 cm diameter) circumscribed tumor.[3] According to literature, the prognosis of t-RCC in pediatric age group remains favorable in general. Moreover, adult patients with t-RCC have worse prognosis in comparison to pediatric t-RCC. However, a meta-analysis has confirmed worse prognosis of pediatric TFE3-positive t-RCC in comparison to TFE3-negative pediatric RCC.[6]{Table 1}

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Revolving fund of the Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi - 221 005, Uttar Pradesh, India.

Conflicts of interest

There are no conflicts of interest.

References

1Magers MJ, Udager AM, Mehra R. MiT family translocation-associated renal cell carcinoma: A contemporary update with emphasis on morphologic, immunophenotypic, and molecular mimics. Arch Pathol Lab Med 2015;139:1224-33.
2Udager AM, Mehra R. Morphologic, molecular, and taxonomic evolution of renal cell carcinoma: A conceptual perspective with emphasis on updates to the 2016 World Health Organization classification. Arch Pathol Lab Med 2016;140:1026-37.
3Liu N, Wang Z, Gan W, Xiong L, Miao B, Chen X, et al. Renal cell carcinoma associated with xp11.2 translocation/TFE3 gene fusions: Clinical features, treatments and prognosis. PLoS One 2016;11:e0166897.
4Shemin Z, Sreehari S, Jojo A. Renal cell carcinoma with Xp11.2 translocation/TFE3 gene fusions-experience from a tertiary care hospital in Kerala, India. J Histol Histopathol 2015;2:6. http://dx.doi.org/10.7243/2055-091X-2-6
5Armah HB, Parwani AV. Xp11.2 translocation renal cell carcinoma. Arch Pathol Lab Med 2010;134:124-9.
6Qiu Rao, Bing Guan, Zhou XJ. Xp11.2 translocation renal cell carcinomas have a poorer prognosis than non-xp11.2 translocation carcinomas in children and young adults: A meta-analysis. Int J Surg Pathol 2010;18:458-64.