Combined Immunohistochemistry for the "Three 7" Markers (CK7, CD117, and Claudin-7) Is Useful in the Diagnosis of Chromophobe Renal Cell Carcinoma and for the Exclusion of Mimics: Diagnostic Experience from a Single Institution.

Jun Zhou,Peipei Zhang,Xiaoqun Yang,Chaofu Wang,Luting Zhou

doi:10.1155/2019/4708154

Jun Zhou, Peipei Zhang + Show 3 more

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https://doi.org/10.1155/2019/4708154

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Journal: Disease markers	Publication Date: Oct 13, 2019
Citations: 13	License type: CC BY 4.0

Affiliation: Shanghai Jiao Tong University

Abstract

Background There is a morphological overlap among renal epithelial tumors, particularly chromophobe renal cell carcinoma (CHRCC), clear cell renal cell carcinoma (CCRCC), renal oncocytoma (RO), and papillary renal cell carcinoma (PRCC). Discriminating between these tumors is important but sometimes challenging. This study is aimed at evaluating the clinical usefulness of the combined immunochemistry for the “three 7” markers (CK7, CD117, and Claudin-7) to distinguish chromophobe renal cell carcinoma from these mimics. Methods Immunochemical staining for CK7, CD117, and Claudin-7 was performed in 68 CHRCCs, 199 CCRCCs, 32 ROs, and 30 PRCCs. Fluorescence in situ hybridization (FISH) was performed in some cases to exclude CCRCC and PRCC. The sensitivity (SE) and specificity (SP) for CHRCC as well as the immunoreactivity of each marker and their combinations were statistically evaluated. Results High positive rates for CK7 (94%), CD117 (87%), Claudin-7 (94%), and their combinations (CK7+CD117, 79%; CK7+Claudin-7, 88%; CD117+Claudin-7, 82%; CK7+CD117+Claudin-7, 76%) were observed in CHRCC compared to those in CCRCC, RO, and PRCC, with increasingly higher SP when combinations of the “three 7” markers were applied (CK7, 0.80; CD117, 0.82; Claudin-7, 0.78; CK7+CD117, 0.95; CK7+Claudin-7, 0.97; CD117+Claudin-7, 0.97; CK7+CD117+Claudin-7, 1). Conclusion CK7, CD117, and Claudin-7 are frequently expressed in CHRCC with high specificity. We recommend the routine use of these 3 markers as a routine panel when making a differential diagnosis of CHRCC and excluding other mimics.

Highlights

There is a morphological overlap among renal epithelial tumors, chromophobe renal cell carcinoma (CHRCC), clear cell renal cell carcinoma (CCRCC), renal oncocytoma (RO), and papillary renal cell carcinoma (PRCC)
Sixty-four CHRCCs, 199 CCRCCs, 32 PRCCs, and 30 ROs were eventually included in our analysis
The 68 CHRCCs contained 55 classical (Figure 1(a)), 5 hybrid oncocytic/chromophobe (HOCT; Figure 1(i)), and 8 eosinophilic (Figure 1(e)) variants, and one case of the latter had a focal area of sarcomatoid change

Summary

Introduction

There is a morphological overlap among renal epithelial tumors, chromophobe renal cell carcinoma (CHRCC), clear cell renal cell carcinoma (CCRCC), renal oncocytoma (RO), and papillary renal cell carcinoma (PRCC). Discriminating between these tumors is important but sometimes challenging. CHRCC is typically arranged in a sold-sheet pattern separated by a thin, incomplete, and hyalinized vascular septa [4]. Other configurations, such as nested, tubular, trabecular, cystic, alveolar, and focal papillary areas, have been appreciated [4]. Two distinct subtypes of CHRCC have been described, that is, a typical variant and an eosinophilic variant; the classical type features a predominance of large polygonal cells with a pale and distinct cell membrane, and the eosinophilic variant demonstrates smaller cells with fine oxyphilic granularity [2, 5]

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