# An Extremely Rare Case of Squamous Cell Carcinoma Following Treatment for External Auditory Canal Papilloma

## TL;DR

A rare case of squamous cell carcinoma developed in a woman's ear canal after prior treatment for a papilloma and earlier radiotherapy.

## Contribution

This paper presents an extremely rare case of radiation-induced squamous cell carcinoma following prior treatment for a papilloma.

## Key findings

- A squamous cell carcinoma developed 9 years after papilloma excision and 20 years after radiotherapy.
- The case highlights the need for early diagnosis and multiple biopsies in suspected auditory canal malignancies.
- Re-irradiation is not feasible for radiation-induced cancers, emphasizing the importance of curative resection.

## Abstract

The case is of a 60-year-old woman with a history of radiotherapy for parotid adenoid cystic carcinoma. Twenty years after irradiation, a papilloma developed in the left external auditory canal. Nine years after excision of the papilloma, a squamous cell carcinoma developed in the same region. This is a rare case of squamous cell carcinoma following treatment for a papilloma and is considered radiation-induced cancer. Because re-irradiation is not possible as a treatment for radiation-induced cancer, it is necessary to diagnose the cancer early so that curative resection is possible. Multiple biopsies should be considered when malignancy is suspected because a single biopsy may not be sufficient to diagnose an auditory canal tumor.