This journal only 2019, Number 1 Neumol Cir Torax 2019; 78 (1) Fibrous solitary tumor of the pleura: Factors associated with malignant behavior and relapse. Institutional experience Ríos-Pascual S, Vázquez-Minero JC, Garza-Jiménez GO, López-Luna JJ, Islem-Gamboa T Full text How to cite this article 10.35366/NT191D × DOI DOI: 10.35366/NT191D URL: https://dx.doi.org/10.35366/NT191D Language: Spanish References: 11 Page: 25-31 PDF size: 308.92 Kb. Key words: Fibrous solitary tumor of the pleura, pleural neoplasms, malignancy, relapse. ABSTRACT Introduction: The fibrous lone tumor of the pleura represents less than 5% of the primary pleural tumors, from 12 to 32% can have malignant behavior with local recurrence and metastasis. The diagnostic study of choice is the computed tomography of thorax. Most originate in the visceral pleura and are pediculated. The treatment is surgical resection en bloc due to the high probability of recurrence, with margins of 1-2 cm. 9% of cases have recurrence. Objectives: Identify factors related to malignant behavior and recurrence. Material and methods: Observational, descriptive, retrospective and transversal study. All patients undergoing resection of TFSP are included in the National Institute of Respiratory Diseases, from January 2008 to December 2017. Results: 26 patients are included, most frequently pediculated tumors dependent on the visceral pleura, 92% manifested symptoms, mainly dyspnoea. Eighteen benign and eight malignant, of which two relapsed, there was death associated with the tumor in two cases. Conclusions: The factors related to malignant behavior were the presence of general symptoms (p = 0.013), weight loss greater than 10 kg in the last six months (p = 0.004) and invasion of adjacent structures (p = 0.020). The factors related to recurrence were the presence › 4 mitoses/10 high power fields (p = 0.018), weight loss greater than 10 kg in the last six months (p = 0.046), invasion of adjacent structures (p = 0.030) and suboptimal surgical resection (p = 0.003). Fibrous lone tumor of the pleura is a tumor of uncertain biological behavior, therefore, factors associated with malignancy and recurrence should be investigated. The treatment is surgical resection en bloc and if malignancy or recurrence criteria are present, adjuvant therapy is required. REFERENCES Franzen D, Diebold M, Soltermann A, et al. Determinants of outcome of solitary fibrous tumors of the pleura: an observational cohort study. BMC Pul Med 2014;14:138-142. doi: 10.1186/1471-2466-14-138. Abu Arab W. Solitary fibrous tumours of the pleura. Eur J Cardiothoracic Surg 2012;41(3):587-597. doi: 10.1093/ejcts/ezr009. Boddaert G, Guiraudet P, Grand B, et al. Solitary fibrous tumors of the pleura: a poorly defined malignacy profile. Ann Thorac Surg 2015;99(3):1025-1031. doi: 10.1016/j.athoracsur.2014.10.035. England DM, Hochholzer L, McCarthy MJ. Localized benign and malignant fibrous tumors of the pleura. A clinicopathologic review of 223 cases. Am J Surg Pathol 1989;13(8):640-658. Schmid S, Csanadi A, Kaifi JT, et al. Prognostic factors in solitary fibrous tumors of the pleura. J Surg Res 2015;195(2):580-587. doi: 10.1016/j.jss.2015.01.049. Lanhon B, Mercier O, Fadel E, et al. Solitary fibrous tumor of the pleura: outcomes of 157 complete resections in a single center. Ann Thorac Surg 2012;94(2):394-400. doi: 10.1016/j.athoracsur.2012.04.028. Cardinale L, Ardissone F, Garetto I, et al. Imaging of benign solitary fibrous tumor of the pleura: a pictorial essay. Rare Tumors 2010;2(1):e1. doi: 10.4081/rt.2010.e1. Tapias LF, Mercier O, Ghigna MR, et al. Validation of a scoring system to predict recurrence of resected solitary fibrous tumors of the pleura. Chest 2015;147(1):216-223. doi: 10.1378/chest.14-1180. Liu M, Liu B, Dong L, Liu B. Recurrent intrathoracic solitary fibrous tumor: Remarkable response to radiotherapy. Ann Thoracic Med 2014;9(4): 245-247. doi: 10.4103/1817-1737.140142. Yokoi T, Tsuzuki T, Yatabe Y, et al. Solitary fibrous tumour: significance of p53 and CD34 inmunoreactivity in its malignant transformation. Histopathology 1998;32(5):423-432. de Perrot M, Fischer S, Bründler MA, Sekine Y, Keshavjee S. Solitary fibrous tumors of the lleura. Ann Thorac Surg 2002;74(1):285-293.