Naser Masoudi
1, Mohammad Reza Pashaei
2, Fatemeh Hosseinzadeh
3* 
1 Surgical Department, Imam Khomeini Hospital, University of Medical Sciences, Urmia, Iran.
2 Department of Internal Medicine, Gastroenterology and Hepatology Section, University of Medical Sciences, Urmia, Iran.
3 Operating Room Department, Nursing Faculty, University of Medical Sciences, Khoy, Iran.
*Corresponding Author: Correspondence to Fatemeh Hosseinzadeh, Operating Room Department, Nursing Faculty, University of Medical sciences, Khoy, Iran. Tel:+98 9399824780, Email: , Email:
fatemeh.hosseinzadeh4780@gmail.com
Abstract
Proliferating trichilemmal tumor (PTT) is a scarce tumor of exterior root sheath that appears to grow within the wall of a pre-existing pilar cyst in most cases. This report presents a case of malignant PTT in the posterior sacrum of a 33-year-old man presenting with limited mobility and a history of paraplegia.