ARC Journal of Clinical Case Reports Volume 8, Issue 1, 2022, PP 1-7 ISSN No. (Online) 2455-9806 DOI: http://dx.doi.org/10.20431/2455-9806.0801001 www.arcjournals.org ARC Journal of Clinical Case Reports Page 1 Solitary Fibrous Tumor / Naso-sinus Hemangiopericytoma: Diagnostic and Therapeutic Management Fatima Safini* 1 , Asmaa Naim 2, , Zineb Bouchbika 3 , Bouchra Amaoui 1,4 , Hicham El Attar 5 1 Department of radiotherapy, Regional Oncology Center of Agadir, Morocco. 2 Casablanca Cancer Center, Radiotherapy Department, Cheikh Khalifa International University Hospital, Casablanca, Morocco; Mohammed VI University of Health Sciences (UM6SS), Casablanca, Morocco 3 Department of Oncology and Radiotherapy, CHU Ibn Rochd, Casablanca, Morocco, 4 Bouchra Amaoui, Department of Radiotherapy, Faculty of Medicine and Pharmacy of Agadir, Ibn Zohr University. Morocco 5 Moulay Driss Premier Anatomopathological Study Laboratory, Casablanca, Morocco 1. INTRODUCTION Hemangiopericytoma (HP) It is a vascular tumor that starts from pericytes, cells located in the walls of capillaries. It was first described by Stout and Murray in 1942 [1]. It is a tumor that has great histopathological similarities to solitary fibrous tumors (TFS). TFS is a spindle cell tumor of mesenchymal origin, originally described by Wagner in 1870 and Klemperer in 1931 [2]. It usually occurs in the pleura but can also start in the head and neck, including the nasosinusal cavity [1,2]. Thus, these two histological entities have led to much debate among pathologists to determine the best way to differentiate between TFS and HPC given the great histopathological and clinical similarities and the lack of clear diagnostic criteria [3]. Also, at the molecular level, fusion abnormalities of the NAB2-STAT6 genes and over expression of STAT6 have been identified in both TFS and HPC. Based on all these data, these two previously separate entities have been unified into a single entity in the new WHO classification of soft tissue and bone thus creating a new concept which is the solitary fibrous tumor / hemangiopericytoma (TFS / HP) [ 4.5]. It is a tumor characterized by its slow progression, its potential for local invasion and destruction of adjacent structures [1]. It is found in 15% of cases in the head and neck region and the nasosinus location is rare [5,6]. We describe the case of a locally advanced inextirpable large TFS / HP of the nasal cavity initially treated with exclusive radiotherapy. 2. CASE REPORT This is a 46-year-old man, married and father of 5 children, with no particular pathological history, whose history of the disease dates back to 8 months before the diagnosis by the progressive installation of a unilateral right nasal obstruction associated with epistaxis aggravated by exophthalmos and right blindness. All of this evolving in a context of conservation of the general condition. The clinical examination revealed a right nasal Abstract: The Hemangiopericytoma is a perivascular tumorwith uncertain malignant potential. The nasosinusal location is rare and differs from other locations by its low grade and its highest rate of recurrence. We report the case of a hemangiopericytoma of the nasal cavity in a 46-year-old patient, diagnosed with locally advanced stage with bone destruction and right blindness. Surgical excision was impossible. The patient received exclusive radiotherapy using intensity modulated radiation therapyand a dose of 70 Gywas delivered.After one year, the patient presented a local progression of the tumor, which required reirradiation by stereotaxic radiotherapy and received systemic chemotherapy. Keyword: Hemangiopericytoma, solitary fibrous tumor,nasal cavity, diagnoses, treatment, *Corresponding Author: Fatima Safini, Department of radiotherapy, Regional Oncology Center of Agadir, Morocco