Malignant proliferating trichilemmal cyst: a case report with review of literature.

Proliferating trichilemmal cyst is a rapidly growing large cutaneous adnexal neoplasm occurring on the head and neck region of elderly women. Malignant transformation has rarely been reported in these lesions. We describe here a 85-year-old lady who presented with a large ulcerated growth over the scalp for one year duration. Incisional biopsy revealed proliferating trichilemmal cyst with malignant transformation. She underwent wide local excision of this growth. She is alive and without evidence of disease after 14 months of follow up. Because of limited number of cases reported in literature, management of malignant proliferating trichilemmal cyst is controversial. Treatment mainly entails wide local surgical excision. Many other adjuvant modalities have been tried. This paper presents the diagnosis and management of one case of malignant proliferating trichilemmal cyst followed by review of the literature.