Huge solitary fibrous tumor of the pleura

Clinical History

A 45-year-old female non-smoker with back pain and no relevant clinical history performed a plain film of the dorsal spine suggesting the presence of a huge para-vertebral mass.

Imaging Findings

Chest radiograph showed a well-defined, large paramediastinal lesion in the right lung(Fig 1). Contrast-enhanced CT confirmed the presence of a single, well-defined, lobulated, solid mass, 12x7cm, with heterogeneous enhancement. The mass exhibited smoothly tapering margin at the junction with visceral pleura that extended from subcarinal mediastinum to the posterolateral right lung base, causing compression on heart, mediastinum and oesophagus and subsegmental atelectasis of the surrounding parenchyma, without ipsilateral pleural effusion (Fig 2). No hilar or mediastinal lymphadenopathy was detected. CT guided cutting-needle biopsy was negative for malignant cells and revealed the presence of inflammatory and fibrotic cells. Subsequent angiography showed vascular afferences from right bronchial and intercostal arteries (Fig 3), which were promptly embolised. Surgery confirmed the presence of a huge soft-tissue highly vascularized mass, (Fig 4) in the right pleural cavity compressing without infiltrating the adjacent structures. One and two years follow-up CT showed no recurrence.

Discussion

Solitary Fibrous Tumour of the Pleura (SFTP) is a benign mesenchymal tumour that arises, usually, from the pleura. The term benign mesothelioma was abandoned when the origin from mensenchymal tissue was determined allowing to distinguish SFTP from diffuse, aggressive epithelial mesothelioma [1-3]. Although the tumor is more commonly intrathoracic, rarely can it be described as extrathoracic, taking origin from peritoneum or pericardium, or with a nonserosal origin from meninges, thyroid, salivary glands, breast and kidney [1, 4]. Fibrous tumour occurrence is more common in the fifth decade, but epidemiology is not clear, due both to the rarity of this tumour and to the lack of symptoms at the early stages of the disease. However, recently, with improvements in diagnostic imaging techniques, the rate of diagnosis is increasing [1, 5]. Any SFTP shall undergo surgical removal followed by histological analysis. Our patient, preoperatively, underwent endoarterial embolisation to decrease hypervascular afflux and facilitate surgery. The diagnosis was confirmed at the anatomic-pathological evaluation. Macroscopically the SFTP is a dense fibrous tissue, arising from the visceral pleura to which is stuck by a peduncle, with possible areas of haemorrhage and necrosis. Microscopically, the typical pattern is a "patternless pattern", with hypercellularity and fibrotic areas [6]. A preoperative diagnosis is possible through a cutting-needle biopsy. Imaging has a crucial role for diagnosis, not only for the detection of the mass, but also for determining the pleural origin of the tumour and the relationship with the surrounding parenchyma, the mediastinum and the chest wall. SFTP usually appears on chest radiograph as a well-defined, sometimes lobulated, extrapulmonary solitary mass, of homogeneous opacity, in broad contact with the chest wall; it can be associated with reactive ipsilateral pleural effusion. At CT, the SFTP looks like an inhomogeneous solitary bulky well-defined solid mass, originating from the visceral pleura, occasionally compressing adjacent mediastinal structures, and with inhomogeneous contrast enhancement. Preoperative CT is useful in surgical planning and in evaluating the features that are associated with poor prognosis (malignant behaviour of SFTP), such as ipsilateral pleural effusion and involvement of the parietal pleura.

Differential Diagnosis List

Final Diagnosis

Solitary fibrous tumour of the pleura

URL:	https://www.eurorad.org/case/9927
DOI:	10.1594/EURORAD/CASE.9927
ISSN:	1563-4086