Malignant Solitary Fibrous Tumour of the Visceral Pleura—Report of a Case—

Abstract

A 57-year-old woman presented to our hospital with dyspnea and chest pain of which she had been aware. A chest CT scan revealed an 18 × 13 cm chest wall tumor in the right thoracic cavity. CT-guided percutaneous needle biopsy led to a diagnosis of solitary fibrous tumor (SFT). It was difficult to differentiate whether the tumor was benign or malignant based on CT, MRI and FDG-PET findings. In December 2020, we performed thoracoscopic-assisted tumor excision. The histopathological study revealed patternless proliferation of spindle-shaped cells. The mitotic figure was 16/10HPF. Immunostaining studies showed CD34 positive and STAT6 positive. From these findings, we diagnosed the case as high-risk malignant SFT. The surgical stump was negative, indicating that a surgical complete resection could be achieved. No adjuvant chemotherapy was added, and the patient has been followed without any therapies.

Malignant SFT is an extremely rare entity, and its diagnostic criteria are still obscure. However, the risk of recurrence has been described in a variety of reports. We here present a case of SFT which was diagnosed as malignant and treated by surgical resection, with literature review.