# Anal Squamous Cell Carcinoma with Bilateral Renal Metastases: A Rare Presentation with Literature Review

## TL;DR

This paper reports a rare case of anal cancer spreading to both kidneys and reviews other unusual metastatic cases to highlight the importance of recognizing atypical cancer presentations.

## Contribution

The novelty lies in presenting a rare bilateral renal metastasis case of anal squamous cell carcinoma and compiling a literature review on uncommon metastatic sites.

## Key findings

- Anal squamous cell carcinoma can rarely metastasize to both kidneys.
- Only one prior case of renal metastasis from anal cancer has been reported.
- Unusual metastatic sites should be considered in clinical practice to improve diagnosis and treatment.

## Abstract

While anal squamous cell carcinoma typically presents with metastases to the liver or lungs, rare metastases sites have been reported. Here, we present a case of rare metastasis to both kidneys and review other cases of rare metastatic sites available in the literature. These cases should serve as reminders that cancers, including anal squamous carcinoma, can present in an atypical manner and increased awareness of these variations is warranted.

Anal squamous cell carcinoma (ASCC) is a rare malignancy of the lower gastrointestinal tract, with distant metastases typically involving the liver and lungs. Metastasis to the kidneys is uncommon, and only one prior case has been reported in the literature. Herein, we report a rare presentation of a patient with biopsy-confirmed metastatic ASCC presenting as bilateral renal lesions. We then provide a review of the literature for rare metastatic presentations of ASCC, highlighting all the cases described in the literature. Clinicians should maintain a high index of suspicion for unusual metastatic sites, perform targeted imaging and biopsy when indicated, and consider systemic therapies to optimize outcomes in rare metastatic presentations.