대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Localzied fibrous tumor of the pleura

Radiologic Findings

Liver dynamic CT scans was performed for evaluation of known hepatocelluar carcinoma. Transverse CT images show a well defined mass around the azygoesophageal recess. The mass demonstrate homogeneous attenuation on a precontrast image. After injection of the contrast media, the mass shows peripheral enhancement on arterial phase and persistent strong enhancement on delayed phase with centripetal pattern. On coronal reconstructed CT image, the mass shows beak-like attachment to the mediastinum showing smoothly tapered margin on its cranial and caudal end. Chest radiograph demonstrate bulging contoured mass-like opacity at right paravertebral area.
VATS excision was performed. The mass was located in the mediastinum in operative field. Pathology with immunohistochemical stains show benign spindle cell lesion with dense collagen lay down, favor solitary fibrous tumor, 3 x 2.8 x 1.9 cm, with clear resection margin
This is a case of localized fibrous tumor of the pleura, located in mediastinum, showing different enhancement features compared with metastasis (or metastatic lymphodenopathy) of underlying HCC patient.

Brief Review

Localzied fibrous tumor of the pleura (LFTP) is mesenchymal neoplasm, usually discovered incidentally on chest radiographs of asymptomatic patients. LFTPs are lobulated soft-tissue masses, which are often described as pedunculated lesions arising from the visceral pleura. Approximately 70 to 80% of these tumors arise from visceral pleura, with the remainder arising from the parietal pleura. LFTP exist in the costal compartment of pleura, within an interlobar fissure, along pleural surface of mediastinum, along the diaphragmatic pleura and rarely within the lung parenchyma.
CT findings are strictly dependent on tumor size. In case of small SFTP, CT more frequently typically demonstrates a homogeneous well defined, non-invasive, lobular, soft-tissue mass, usually adjacent to the chest wall or within a fissure, showing an obtuse angle with the pleural surface. Large lesion is usually heterogeneous and may not exhibit CT features suggestive of focal pleural tumors. Such lesions usually form acute angles with the adjacent pleural surface mimicking a subpleural pulmonary mass that could be misdiagnosed as peripheral lung cancer or metastasis. Enhancement after contrast medium is typically intense and heterogeneous with central areas of low attenuation.
Excision is curative in the majority of patients, although a small number of lesions can recur, undergo malignant transformation, or metastasize.

References

1. Rosado-de-Christenson ML, Abbott GF, McAdams HP et al. Localized Fibrous Tumors of the Pleura. RadioGraphics 2003; 23:759-783
2. Wignall OJ, Moskovic EC, Thway K et al. Solitary Fibrous Tumors of the Soft Tissues: Review of the Imaging and Clinical Features With Histopathologic Correlation AJR 2010; 195: W55-W62
3. Cardinale L, Ardissone F, Garetto I, et al. Imaging of benign solitary fibrous tumor of the pleura: a pictorial essay. Rare Tumors. 2010 31;2(1):e1

Keywords

pleura, benign tumor,