Malignant Transformation of a Sebaceous Cyst Into Squamous Cell Carcinoma in an Elderly Male Patient

Malignant transformation of sebaceous cysts into squamous cell carcinoma (SCC) is exceptionally rare. We report the case of a 65-year-old man with a long-standing anterior chest wall sebaceous cyst that ulcerated and rapidly enlarged over three months. Examination revealed a fungating lesion without chest wall invasion. The patient underwent wide local excision with adequate margins and primary closure, recovering uneventfully. Histopathology confirmed moderately differentiated SCC. This case underscores the importance of early biopsy and surgical management when chronic cystic lesions develop ulceration, rapid growth, or atypical changes.