# Sinonasal metastasis as the initial presentation of renal clear cell carcinoma: a dual-center retrospective study and proposed diagnostic algorithm

## TL;DR

This study examines kidney cancer cases that first showed up in the nose area, aiming to improve early detection and treatment.

## Contribution

A diagnostic algorithm is proposed to reduce delays in diagnosing renal clear cell carcinoma presenting with sinonasal symptoms.

## Key findings

- Endoscopic resection combined with systemic therapy improved outcomes in oligometastatic ccRCC.
- Three patients remained disease-free for up to 50 months after treatment.
- A structured diagnostic pathway is recommended for unexplained sinonasal symptoms to enable early diagnosis.

## Abstract

To investigate the clinical characteristics, diagnostic approaches, and treatment strategies for metastatic clear cell renal cell carcinoma (ccRCC) initially presenting with sinonasal involvement, thereby enhancing early recognition and optimal management.

We conducted a retrospective dual-center cohort study on five patients with ccRCC who presented with initial nasal symptoms. These patients were admitted to the otolaryngology departments of two regional medical centers between August 2011 and September 2024. All patients underwent endoscopic sinus surgery, and a detailed review of the patients’ clinical presentations, imaging and histopathological findings, treatment regimens (endoscopic resection followed by adjuvant therapy), and oncologic outcomes.

All five patients were male, aged 55 to 71 years with a median age of 66 years. Primary symptoms included epistaxis (3/5), nasal obstruction (5/5), and decreased vision (1/5). The diagnosis was confirmed by preoperative biopsy in three cases and intraoperative pathological examination in the remaining two. Complete tumor resection was achieved via endoscopic nasal surgery. Over a follow-up ranging from 17 to 50 months, three patients were alive with no evidence of disease (ANED) at 40, 48 and 50 months, respectively; one patient with concurrent lung metastasis died at 17 months; and one patient was lost to follow-up at 36 months. The median follow-up was 38 months (range: 17–50).

Our findings support the role of complete endoscopic resection combined with systemic therapy in oligometastatic ccRCC. The proposed diagnostic algorithm provides a structured pathway to mitigate diagnostic delay. Heightened clinical vigilance and the application of such a pathway are essential for early diagnosis and optimal management in patients presenting with unexplained sinonasal symptoms.