Calcifying fibrous tumour of the pleura without gross calcification

Abstract

Key message

Calcifying fibrous tumours of the pleura (CFTP) typically appear as calcified, non-enhancing lesions on chest CT scans. However, enhancing pleural lesions can mimic malignancy like mesothelioma. We report a rare case that enhancing pleural thickening, confirmed as CFTP through pathological examination, despite the absence of visible calcification on radiological imaging.

A 19-year-old male was referred to our pulmonology clinic for pleural thickening of right side on chest x-ray, which was incidentally found on the Army's enlistment examination (Figure 1A, yellow arrow). He had smoked 1–2 cigarettes per day for 1 year. He had no symptoms and no exposure to asbestos. Non-enhanced chest computed tomography (CT) showed no signs of calcification for the pleural thickening lesions in cross sectional view (Figure 1B, yellow arrows) Contrast-enhanced chest CT showed diffuse thickening of right pleural space involving visceral pleura and right diaphragm with heterogeneous enhancement (Figure 1C, yellow arrows and Figure 1D, yellow arrow and yellow circle). Video-assisted thoracoscopic surgery (VATs) revealed multiple soft mass lesions with irregular shapes at the entire right pleural space extending to diaphragmatic area and visceral pleura (Figure 1E, yellow arrows and yellow circle). The specimen resected from the surgery measured 12.5 × 9.6 × 3.7 cm and showed irregular surface and thickened pleura about 1.4 cm thick (Figure 1F). Haemotoxylin and Eosin staining of the specimen disclosed psamommatous calcification (Figure 1G, yellow arrows). Immunohistochemical staining showed positivity of spindle-shaped cells only for vimentin (Figure 1H) and negativity both for S-100 and CD-34 (Figure 1I,J, respectively) that are comparable with calcifying fibrous tumour. A follow-up chest CT at 7 months later showed no local recurrence suggesting complete surgical resection.

To our best knowledge about calcifying fibrous tumour of the pleura (CFTP), calcification was demonstrated on radiologic image assessment in almost all reported cases.^1,2 Although chest CT slice thickness, 3 mm for this case, should be considered for interpreting chest CT results, interestingly, this case showed no apparent sign of calcification either on chest x-ray or chest CT. Based on our experience, physicians need to suspect the possibility of CFTP with pleural thickening and features of malignancy irrespective of gross calcification on chest x-ray and/or CT.

AUTHOR CONTRIBUTIONS

Hwan Jin Lee was involved in writing original draft, writing–review and editing and final approval of the manuscript. Young Chul Lee and Jase Seok Jeong were involved in writing original draft, reviewing, and the final approval of the manuscript and served as a supervisors throughout the manuscript writing process.

FUNDING INFORMATION

This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. RS-2023-00236157; JSJ). This paper was supported by Fund of Biomedical Research Institute, Jeonbuk National University Hospital. No competing financial interests exist.

CONFLICT OF INTEREST STATEMENT

None declared.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

ETHICS STATEMENT

The authors declare that appropriate written informed consent was obtained for the publication of this manuscript and accompanying images.