Malignant Proliferating Trichilemmal Tumor

**Semantic type:** Neoplastic Process

**Definition:** A rare proliferating trichilemmal tumor with malignant morphological characteristics and the potential for distant metastases.

**Synonyms:** - Malignant Pilar Tumor - Malignant Proliferating Pilar Tumor - Malignant Proliferating Trichilemmal Cyst - Malignant Proliferating Tricholemmal Tumor - Malignant neoplasm with pilar differentiation (morphologic abnormality)