# Metastasis of Small Cell Lung Cancer to the External Auditory Canal: A Case Report

## TL;DR

A rare case of small cell lung cancer spreading to the ear was successfully treated with chemotherapy, improving the patient's hearing and symptoms.

## Contribution

This case report presents a rare instance of chemotherapy effectively treating ear symptoms caused by lung cancer metastasis to the external auditory canal.

## Key findings

- Computed tomography revealed masses in the external auditory canal, lung, and pancreas.
- Chemotherapy with carboplatin and etoposide reduced metastatic lesions and improved hearing.
- Thyroid transcription factor 1 positivity confirmed the primary tumor originated in the lung.

## Abstract

Patients with lung cancer often develop distant metastases; however, metastasis to the external auditory canal is rare. We report the case of a 77‐year‐old man who presented with left‐sided hearing loss, otalgia, and a red mass in the left external auditory canal. Computed tomography revealed masses in the left external auditory canal, lung, and pancreas. Histopathological analysis confirmed small cell lung cancer, with thyroid transcription factor 1 positivity in multiple lesions, suggesting a primary tumor in lung. Treatment with carboplatin and etoposide led to a reduction in metastatic lesions, including those in the external auditory canal, and improved hearing impairment. This case highlights a rare instance in which chemotherapy improved ear symptoms in a patient with small cell lung cancer metastasis to the external auditory. Written informed consent was obtained from the patient for the publication of this case report and accompanying images.

We report a rare case in which chemotherapy improved ear symptoms in a patient with small cell lung cancer metastasis to the external auditory canal. Multimodal therapy is often required for the treatment of cancer to the external auditory canal, whereas chemotherapy alone for external auditory canal metastasis with high sensitivity to anticancer drugs is suggested to improve ear symptoms and quality of life.