A 36-year-old female was referred to our hospital for further evaluation on abnormal finding in the computed tomography (CT). The patient had chest discomfort and mild dyspepsia for 3 months but otherwise healthy. She never smoked, had no previous medical history including trauma or pulmonary disease including tuberculosis. Her blood laboratory tests were unremarkable. In the primary clinic, chest imaging evaluation was done. On axial image of chest CT, there was a chain of non-enhancing small nodules in the left hemi-diaphragmatic pleura with fat containing lesion (Fig. 1A and B). The chest magnetic resonance imaging (MRI) also showed similar findings from chest CT without chest wall invasion (Fig. 1C). On positron emission tomography-computed tomography (PET-CT) represented pleural based lesions without significant FDG uptake in left lower lobe of the lung (Fig. 1D). The leading initial radiographic impression was pleural lipomatosis and was referred to thoracic surgeon to evaluate the necessity of surgical resection. Due to patient's symptom and growing rate of tumor, the patient underwent video assisted thoracotomy (VATS) of pleural exploration.
During the operation, a total of twenty-five smooth glossy white round-shaped, pearl-like lesions were observed in the pleura (Fig. 2A and B). The largest thoracolithiasis found in was 20mm. Most nodules were freely movable and discovered around the dependent position of the lung. There were some nodules that seemed to be originating from visceral & parietal pleura. There was no adhesion between the nodules and the organs around, and all the nodules were completely removed. Around the diaphragmatic pleura and nearby parietal pleura showed inflammatory change with minimal amount of serous effusion but otherwise no other abnormality was detected. Histopathological examination showed extensive necrotic fatty tissue at its center surrounded by fibrosis, as assumed from the thoracic image findings (Fig. 2C). The postoperative recovery was uneventful. The patient was symptom free after the surgical removal, suggesting thoracolithiasis was associated with chest discomfort. She is still being followed up for about two years after the surgical removal with chest CT every year and the last CT scan showed no remarkable finding in the pleural cavity, lungs or mediastinum.