title: Hemangiopericytoma of the infratemporal fossa: progression toward malignancy in a 30-year history.
abstract: Hemangiopericytoma is a rare vascular tumor first described by Stout and Murray in 1942 and characterized by a proliferation of Zimmermann's pericytes, smooth muscle cells arranged around blood vessels. This tumor presents as a slowly enlarging painless mass. Diagnosis with certainty is often a difficult one because of the close likeness with other spindle cell tumors; it requires the help of immunohistochemical techniques and sometimes ultrastructural techniques. Only 15% of hemangiopericytomas are localized in the cervicofacial region; in particular, occurrence in the infratemporal fossa is an exceptional occurrence. In this article, we report an unusual case of recidivate hemangiopericytoma of the infratemporal fossa that has progressively assumed features of malignancy over 30 years. The hemangiopericytoma relapse potentiality is elevated, even when the histologic characteristics of the tumor indicate a low aggressivity, and therefore every hemangiopericytoma must be considered to have malignant potential. In conclusion, the unpredictable behavior of hemangiopericytoma requires a radical primary treatment to avoid the risk of relapses that always are frequent and aggressive.
authors.affiliation: Division of Maxillofacial Surgery, Ospedale Maggiore della Carità, University of Piemonte Orientale Amedeo Avogadro, Novara, Italy. brucolim@libero.it
authors.forename: Matteo
authors.initials: M
authors.lastname: Brucoli
authors.forename: Mariangela
authors.initials: M
authors.lastname: Giarda
authors.forename: Guido
authors.initials: G
authors.lastname: Valente
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Benech
mesh_terms: D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D018450:Disease Progression; D004730:Endothelium, Vascular / Q000473:pathology; D005500:Follow-Up Studies; D006393:Hemangiopericytoma / Q000473:pathology*; D006801:Humans; D006818:Hyalin; D008297:Male; D008940:Mitotic Index; D009130:Muscle, Smooth / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D020286:Pericytes / Q000473:pathology; D019292:Skull Base Neoplasms / Q000473:pathology*; D013701:Temporal Bone / Q000473:pathology*
chemical_list: D018952:Antigens, CD34