RESUMO
BACKGROUND: Malignant proliferating trichilemmal tumor is a rare skin tumor that affects mainly older women. It mimicks differential squamous cell carcinoma and its biological behavior is unpredictable. OBJECTIVE: To report on a new case of malignant proliferating trichilemmal tumor of the scalp and to describe the clinical and histopathologic findings. METHODS: A tumor measuring 2 cm was surgically excised with a 0.5 cm conservative margin of normal tissue RESULTS: Based on the histopathologic findings of tumor, this case was diagnosed as proliferating trichilemmal tumor of the scalp. Eleven months after tumor resection, the patient is free of disease. CONCLUSION: Malignant proliferating trichilemmal tumor is a rare malignant lesion with an unpredictable biological behavior. After wide excision, long term clinical follow up of the patient for early diagnosis of metastases is judicious.