Case Report: Bilateral Renal Cell Carcinoma With Different Histological and Morphological Features, Clear Cell and Cystic Thyroid-Like Follicular Subtype.

Jinsong Ni,Ni Cui,Jixuan Liu,Yanfang Wang

doi:10.3389/fonc.2021.659706

Abstract

Thyroid-like follicular renal cell carcinoma is a rare subtype of renal cell carcinoma that has only been recently recognized, as most cases involve a solid tumor in one kidney. In this study, we report a rare case of bilateral renal cell carcinoma wherein the tumor in the left kidney was diagnosed as clear cell carcinoma, while the tumor in right kidney as thyroid-like follicular renal cell carcinoma. The difference between this case and the ones described in previous reports is that thyroid-like follicular renal cell carcinoma showed cystic changes on imaging. This suggests that when renal cystic lesions are encountered, we should consider the possibility of such rare tumors.

Highlights

Thyroid-like follicular renal cell carcinoma is a rare tumor, which is not included in the 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs [1]
Most cases reported in the literature are solid tumors, and cystic changes may occur in some tumors
We reported a rare case of bilateral renal tumors, with clear cell carcinoma on the left side and thyroid-like renal cell carcinoma on the right side

Summary

INTRODUCTION

Thyroid-like follicular renal cell carcinoma is a rare tumor, which is not included in the 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs [1]. Most of the reported thyroid follicular renal cell carcinomas are solid tumors, and only one case with cystic changes on imaging has been reported [6]. In patients with this tumor, simple renal cysts and multilocular cystic renal neoplasm of low malignant potential require differential diagnosis. According to the postoperative pathology examination, we observed follicular architecture with micro- and macrofollicles containing eosinophilic secretions or colloid-like material in another area of the right renal cyst wall (Figure 1D). The right renal tumor was diagnosed as thyroid-like follicular renal cell carcinoma with cystic changes, while the left kidney tumor was diagnosed as clear cell renal cell carcinoma. At the time of this writing, the patient is 10 months post-treatment with no clinical or histological evidence of recurrence

DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT