Solitary Fibrous Tumor of the Pleura Presenting as a Giant Thoracic Mass: A Case ReportSadin Zahra¹, Aghajanzadeh Manouchehr¹, Sadin Mohammadreza1, Dadashi Arsalan¹, Mosaffaee Rad Omid¹, Fakher Mosavi Seyed Ali², Foumani Alavi Ali², Tangestaninejad Azita², Farzin Mohaya³Affiliations¹ Department of Thoracic Surgery, Arya Private Hospital, Rasht, Iran² Department of Pulmonology, Arya Private Hospital, Rasht, Iran³ Department of Internal Medicine, Inflammatory Lung Diseases, Arya Private Hospital, Rasht, IranCorresponding Author Sadin ZDepartment of Thoracic and General Surgery, Arya Private Hospital, Rasht, IranEmail: drsadin95@gmail.comPhone number: +98 9113484826Written Informed ConsentWritten informed consent was obtained from the patient for publication of this case report and accompanying images.Key Clinical MessageSolitary fibrous tumors of the pleura are rare and may present as large thoracic masses. Timely imaging and histopathological confirmation are essential for accurate diagnosis and effective surgical management.AbstractSolitary fibrous tumors of the pleura (SFTP) are quite rare and distinct from other pleural tumors such as mesotheliomas. The majority of these tumors are benign, with only a small percentage being malignant. In the early stages, they are often asymptomatic, but as they grow, they can lead to chest pain, dry cough, and shortness of breath because of the pressure they place on nearby structures. In some cases, large tumors can even compress the mediastinal organs. Interestingly, up to 20% of these tumors are linked with hypertrophic pulmonary osteoarthropathy.We report the case of a 62-year-old woman who presented with a large intrathoracic mass. Imaging revealed a 21×15 cm pleural-based tumor suggestive of SFTP. Initial biopsy was inconclusive.The patient underwent successful surgical resection of the tumor. The mass was completely removed with clear margins. Histopathological analysis confirmed the diagnosis of a benign solitary fibrous tumor of the pleura.Keywords:Solitary fibrous tumor, pleura, pulmonary osteoarthropathy, expansive growth, mediastinal shift, surgical treatment.