Pleural fibroma (solitary fibrous tumour of the pleura)

Clinical History

Patient with cough and abnormal chest radiograph.

Imaging Findings

The patient presented with a 2 year history of cough with dirty white sputum. There was no history of shortness of breath, chest pain, haemoptysis or weight loss. A chest x-ray (fig. 1) showed non-specific right basal shadowing. A CT scan (figs 2-5) of the thorax showed a huge lobulated mass filling the right lower lobe. This was biopsied under ultrasound guidance. The histology was reported as showing overall appearances of a solitary fibrous tumour of the pleura (pleural fibroma) with no evidence of malignant cells.

Discussion

Pleural fibromas are rare tumours, accounting for less than 5% of all pleural neoplasms. They are derived from submesothelial mesenchymal cells but are not related to asbestos exposure. Approximately, half the patients with pleural fibromas are asymptomatic but cough, chest pain and dyspnoea may be presenting symptoms, particularly if the tumour is large. Hypertrophic osteoarthropathy (up to 35%) and hypoglycaemia (5%) are other well documented features. These tumours are usually slow growing and surgical excision is usually curative. Local recurrence is reported in about 16% of cases but malignant transformation is rare.
Pleural fibromas usually show soft tissue attenuation on unenhanced CT scans although higher attenuation values may occur due to the high physical density of the collagen content and prominent vascularity. This latter feature can bring about marked enhancement post intravenous contrast although in our case, the tumour enhanced less than the liver.
MR images of the lesion would be expected to show intermediate to low signal change on T1-weighted images and low signal intensity on proton density and T2-weighted images. Enhancement post IV contrast would also be expected on MR. Calcification is seen in approximately 7% of these tumours. Rib erosion is rare.

Differential Diagnosis List

Final Diagnosis

Right sided pleural fibroma

URL:	https://www.eurorad.org/case/2819
DOI:	10.1594/EURORAD/CASE.2819
ISSN:	1563-4086