Abstract
A 71-year-old woman developed a brownish tumor on her left axilla, which had gradually enlarged over the course of a few years. Her medical records revealed that she had received radiation therapy on her left chest and axilla after the surgical treatment of breast cancer about 40 years ago. Physical examination showed a brownish tumor measuring 20×8 mm with an irregular border on the left axilla. The skin around the tumor was free of eruption or unusual pigmentation. According to dermoscopic, and histopathologic findings, the tumor was diagnosed as a basal cell carcinoma (BCC). BCC commonly arises at sun-exposed regions. However, BCC may also arise in damaged skin by radiation. Recently, the frequency of reports of BCCs arising after radiation therapy has been increasing. According to these reports, many of the BCCs arising after radiation therapy were found at regions where BCC is considered to be uncommon, such as the buttock, upper arms, and axilla. For patients with BCCs arising at uncommon regions, we should confirm their history of radiation therapy.
