CASE REPORT article
Front. Oncol.
Sec. Genitourinary Oncology
This article is part of the Research TopicAdvancing Surgical Outcomes for Retroperitoneal TumorsView all 13 articles
Case Report:Spontaneous regression of cystic renal cell carcinoma
Provisionally accepted
- 1Nanchang University Second Affiliated Hospital, Nanchang, China
- 2Nanchang University Jiangxi Medical College, Nanchang, China
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Background: Spontaneous regression (SR) of cystic renal cell carcinoma (CRCC) is extremely rare, and previous reports lack pathological confirmation. In this review, we report a case of spontaneous partial regression of Bosniak grade IV CRCC confirmed by postoperative pathology, and discuss its potential mechanism. Case summary: A 59-year-old female patient with a simple cyst (34*31 mm) in her left kidney was detected by color doppler flow imaging(CDFI) in July 2023. In October 2024, the computed tomography(CT) showed that the lesion had progressed to Bosniak grade Ⅳ cystic mass (60*50 mm), which was not treated. Follow-up magnetic resonance imaging (MRI) in April 2025 showed that the lesion was significantly reduced (25*28 mm). The patient underwent robot-assisted laparoscopic partial nephrectomy, and was pathologically diagnosed with clear cell renal cell carcinoma(ccRCC) after surgery. Conclusions: Despite spontaneous regression, Bosniak grade Ⅳ renal cystic disease requires surgical intervention to confirm the diagnosis and avoid progression. This study provides a new basis for the natural history of high-risk renal cystic lesions and individualized follow-up strategies.
Keywords: Bosniak grade, case report, Clear cell renal cell carcinoma, Cystic renal cell carcinoma, Spontaneous regression, Tumor Microenvironment
Received: 27 Nov 2025; Accepted: 06 Feb 2026.
Copyright: © 2026 Xu, Zhang, Zhang and Hu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Honglin Hu
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