Giant solitary fibrous tumor of the pleura

Abstract

Solitary fibrous tumors are rare mesenchymal tumors accounting for <5% of all neoplasms in the pleura and other sites. A 45-year-old man reported to us with cough and dyspnea. Radiological investigations revealed a giant mass displacing the mediastinum to the left. The tumor weighing 3.0 kg was successfully resected via a right thoracotomy. Histology and immunohistochemistry confirmed a benign tumor. Recurrence and malignant transformation of these benign tumors have been reported. Our patient has been followed up for 4 years with no recurrence.

The Potential Malignancy of a Solitary Fibrous Tumour of the Lung

“…It is widely recognised that SFTPs are rare neoplasms that are predominantly benign with no gender predilection [ 2 , 4 , 5 , 8 , 11 ]. The literature suggests that between 10 and 30% of SFTPs are malignant [ 2 , 7 , 11 ] and display the characteristics described by England et al, that is, hypercellularity, nuclear atypia, >4 mitoses per 10 high-power fields, haemorrhage, and necrosis [ 2 , 4 , 12 ].…”

“…However, authors regard these as relatively nonspecific and recent studies have highlighted the importance of genotyping for NAB2-STAT6 gene fusion, which has been shown to distinguish SFTs from histological mimics [ 9 , 13 ]. Fibrous tumours attached to the pleura were found to originate from the visceral pleura in two-thirds of cases and the parietal pleura in one-third of cases [ 5 , 11 ]. The tumour size can range from between 1 cm and 39 cm [ 11 ] with those larger than 10 cm being malignant [ 11 , 14 , 15 ].…”

“…The tumour size can range from between 1 cm and 39 cm [ 11 ] with those larger than 10 cm being malignant [ 11 , 14 , 15 ]. In addition to size, other macroscopic features indicating malignancy include lack of a pedicle and atypical location, for example, attachment to parietal pleura and inversion into peripheral lung [ 5 , 11 ]. Our case was unusual because the tumour was attached to the visceral pleura via a pedicle—a feature consistent with benign tumours [ 5 , 11 ].…”

“…In addition to size, other macroscopic features indicating malignancy include lack of a pedicle and atypical location, for example, attachment to parietal pleura and inversion into peripheral lung [ 5 , 11 ]. Our case was unusual because the tumour was attached to the visceral pleura via a pedicle—a feature consistent with benign tumours [ 5 , 11 ]. Histological analysis, however, confirmed it to be a malignant SFTP based on immunohistochemistry tests and England's criteria as described earlier.…”

“…Solitary fibrous tumours (SFTs) are rare neoplasms with a reported incidence of 2.8 cases per 100,000 persons per year [ 1 ]. SFTs originate from mesenchymal cells and represent less than 5% of all pleural tumours [ 1 – 5 ]. 80% of SFTs arise from the visceral pleura and may present at any age, although being more frequently encountered between the fifth and eighth decades of life [ 4 – 8 ].…”