LAUSR

AIM To analyse and compare the computed tomography (CT) features of benign and malignant types of histopathologically proven cases of solitary fibrous tumours of pleura (SFTP). MATERIALS AND METHODS Retrospective analysis of preoperative CT images of 28 cases of histopathologically proven and classified SFTP from three participating institutions was performed. Patient demographics and lesion characteristics including size, borders, presence of a pedicle, extension into the fissure, attenuation, enhancement, pleural effusion, and calcifications were recorded and correlated with the final histopathological diagnosis. Type and results of preoperative biopsy were also recorded. Follow-up imaging and the clinical charts were reviewed to identify recurrence. RESULTS Out of 28 cases (15 women and 13 men), 18 were proven to be benign and 10 were malignant. The mean age of patients was 58.1±15.9 and 66.5±11.8 years (p=0.1564) for benign and malignant tumours, respectively. The median (interquartile range) diameter was 6.05 (3.2-10.9) cm for benign and 15.7 (7.1-17.5) cm for malignant type tumours (p=0.0291). Tumours had lobulate borders in 28% (5/18) of benign cases and in 80% (8/10) of malignant cases (p=0.0163). Extension into adjacent fissure was seen in 22% (4/18) of benign lesions and 40% (4/10) of malignant lesions (p=0.40). A pedicle was present in 17% (3/18) of benign and 10% (1/10) of malignant lesions (p=1). Heterogeneous attenuation was present in 61% (11/18) of benign and 90% (9/10) of malignant lesions (p=0.19). Calcification was present in 17% (3/18) of benign tumours and in 70% (7/10) of malignant tumours (p=0.0113). Pleural effusion was present in 6% (1/18) of benign and 40% (4/10) of malignant lesions (p=0.04). Only 1/13 preoperative fine-needle aspirates yielded diagnosis of SFTP. Preoperative diagnosis of SFTP was made in all cases (11/11) with core biopsies. At follow-up (1-10 years, mean 3 years), local recurrence occurred in 3/6 (50%) patients with malignant SFTP and in none of the 10 patients with benign SFTP. CONCLUSION No definite imaging feature to differentiate benign from malignant SFTP was found. Large size, lobulate borders, presence of calcification, and ipsilateral pleural effusion were the only CT features predictive of malignancy. In suspected cases, core biopsies should be performed rather than fine-needle aspiration.