ABSTRACT
Malignant proliferating trichilemmal tumor (MPTT) is an uncommon and malignant tumor of the skin, arising from the outer root sheath of the hair follicle. Most MPTTs occur in the head and neck area and affect the scalp predominantly. However, rarely, MPTT of other anatomical sites, such as back, buttocks, chest, elbow, vulva, mons pubis and nose, have been described. Although the malignant biological behaviour of the neoplasm, the known loco-regional aggression and the potential local and distant recurrences, surgical excision with free margins of normal tissue is generally curative and represents the gold standard of treatment. We describe a case of MPTT arising on the scrotum of 51-year-old man. Through this case and the review of the literature we try to establish the state of the art regarding the clinical aspects, the morphological and immunohistochemical features of this neoplasm. Finally, we underline the exceptionally rare location of the tumor in our case. To the best of our knowledge this is the first case of MPTT arising on scrotum.

IMPACT STATEMENT
Diagnosis and treatment of malignant trichilemmal tumor needs a multidisciplinary approach with a strong clinical-morphological correlation for an accurate diagnosis, particularly when it occurs in exceptionally rare sites.

Full text below.