Proliferating Giant Pilomatrixoma: A Case Report

Pilomatrixoma is a benign adnexal tumor, frequently observed in pediatric and young adult populations, and originates from the hair follicle matrix. While the most common clinical presentation is a subcutaneous nodule, multiple clinicopathological variants have been identified. One such variant is the giant pilomatrixoma, defined by a size of 4 cm or greater, which may mimic malignant neoplasms such as angiosarcoma or amelanotic melanoma in adults. We present the case of a 36-year-old female patient who presented with an exophytic mass on the right cheek, which exhibited rapid growth following trauma. Due to the suspicion of malignancy, an excisional biopsy with a 5 mm margin was performed, and histopathological examination revealed a proliferating pilomatrixoma. This case is noteworthy for presenting two variants: classification by size (giant pilomatrixoma) and histological subtype (proliferative). It is essential to ensure appropriate surgical management, as incomplete excision may lead to local recurrence and/or malignant transformation.