# Unanticipated papillary renal cell carcinoma in a complicated renal cyst: A case of radical nephrectomy following surgical complications

## TL;DR

A rare case of papillary kidney cancer developed in a cyst initially considered benign, leading to emergency surgery and highlighting the need for careful monitoring.

## Contribution

Demonstrates the rare but possible malignant transformation of a Bosniak IIF renal cyst into papillary renal cell carcinoma.

## Key findings

- PRCC was confirmed in a renal cyst previously classified as Bosniak IIF and monitored for three years.
- Intraoperative complications necessitated radical nephrectomy, underscoring surgical unpredictability.
- Imaging limitations were highlighted, as malignancy was not detected preoperatively.

## Abstract

Cystic renal masses are often presumed benign, especially Bosniak I or IIF lesions. Rarely, papillary renal cell carcinoma (PRCC) can arise within these cysts, posing diagnostic and surgical challenges. We report a 40-year-old male with a right renal cyst under surveillance for three years as Bosniak IIF. Progressive growth led to laparoscopic cyst unroofing, but intraoperative findings of a solid mass and significant bleeding necessitated urgent radical nephrectomy. Histopathology confirmed pT2bN0Mx PRCC with solid and pseudopapillary features. This case underscores imaging limitations, the potential for malignancy in low-risk cysts, and the importance of vigilant monitoring, preoperative planning, and patient counseling.

•Rare malignant potential: Papillary renal cell carcinoma can arise within cystic renal lesions initially classified as Bosniak IIF, even after long-term surveillance.•Diagnostic limitations: Imaging, including CT, may not reliably detect malignancy in apparently benign cysts, emphasizing the need for repeat assessment and careful preoperative planning.•Surgical challenges: Unexpected solid components and intraoperative bleeding may necessitate urgent radical nephrectomy, highlighting the importance of patient counseling.•Clinical
implications: Vigilant follow-up, individualized management, and awareness of both oncologic and perioperative complications are essential to optimize outcomes.

Rare malignant potential: Papillary renal cell carcinoma can arise within cystic renal lesions initially classified as Bosniak IIF, even after long-term surveillance.

Diagnostic limitations: Imaging, including CT, may not reliably detect malignancy in apparently benign cysts, emphasizing the need for repeat assessment and careful preoperative planning.

Surgical challenges: Unexpected solid components and intraoperative bleeding may necessitate urgent radical nephrectomy, highlighting the importance of patient counseling.

Clinical
implications: Vigilant follow-up, individualized management, and awareness of both oncologic and perioperative complications are essential to optimize outcomes.