A Pleural Loose Body Mimicking a Pleural Tumor: A Case Report

Formation of a rare curve-shaped thoracolith documented on serial chest computed tomography images: A case report

BACKGROUND

Thoracolithiasis is a rare benign condition that manifests with one or more small nodules in the pleural cavity. In most cases, it is asymptomatic and found incidentally on chest imaging or during thoracic surgery. The thoracolithiasis formation process is rarely documented. Herein, we present a case of a rare, large, curve-shaped thoracolith, the formation of which was documented on serial computed tomography (CT) images.

CASE SUMMARY

A 46-year-old male patient who denied any prior systemic disease was evaluated due to intermittent right-sided lateral chest pain lasting for a year. Chest radiography and CT revealed a circumscribed calcified nodule measuring 3.5 mm in the right lower lung lobe. Nodule biopsy revealed fungal infection, which was treated with antifungal medication. After 2 years of follow-up, the patient developed intermittent chest discomfort caused by pleural adhesions, and underwent video-assisted thoracic surgery with pneumolysis. Postoperatively, he developed empyema, which fully resolved with antibiotic therapy. Thereafter, he was followed up at the outpatient clinic and underwent chest CT twice per year. Over time, we observed thickening of the right distal pleura near the lower posterior mediastinum, and several sporadic calcified nodules with gradually increasing intensity, which eventually merged into a single calcified curve-shaped thoracolith measuring approximately 9 cm in length during the 5-year follow-up.

CONCLUSION

This study documented the formation of a rare thoracolith shape observed for the first time.

Imaging Features of Various Benign and Malignant Tumors and Tumorlike Conditions of the Pleura: A Pictorial Review

Pleural masses may be caused by various conditions, including benign and malignant neoplasms and non-neoplastic tumorlike conditions. Primary pleural neoplasms include solitary fibrous tumor, malignant mesothelioma, and primary pleural non-Hodgkin's lymphoma. Metastatic disease is the most common neoplasm of the pleura and may uncommonly occur in patients with hematologic malignancy, including lymphoma, leukemia, and multiple myeloma. Pleural effusion is usually associated with pleural malignancy. Rarely, pleural malignancy may arise from chronic empyema, and the most common cell type is non-Hodgkin's lymphoma (pyothorax-associated lymphoma). Non-neoplastic pleural masses may be observed in several benign conditions, including tuberculosis, pleural plaques caused by asbestos exposure, and pleural loose body. Herein, we present a review of benign and malignant pleural neoplasms and tumorlike conditions with illustrations of their computed tomographic images.

A rare case of numerous thoracolithiasis with chest discomfort

Thoracolithiasis is a rare benign condition with mobile free bodies in the pleural cavity. It is asymptomatic and mostly found incidentally. Up to our knowledge there is no report of symptomatic numerous thoracolithiasis. We report a very rare case of thoracolithiasis in a 36-year-old female with chest discomfort. Images from computed tomography presented a chain of small non-enhancing nodules in the left hemi-diaphragmatic pleura. Exploratory thoracoscopy was performed and twenty-five mobile pearl like thoracolithiasis were discovered. Histopathology showed extensive necrotic fatty tissue at its center surrounded by fibrosis. The patient was symptom-free after the surgical removal of numerous thoracolithiasis, suggesting thoracolithiasis was associated with chest discomfort.

Thin-section CT findings of thoracolithiasis

PURPOSE

To review thin-section CT findings of thoracolithiasis.

MATERIALS AND METHODS

Thirty-three thin-section CT scans of 9 patients with thoracolithiasis diagnosed between 2008 and 2016 were reviewed for the location, shape, longest diameter, and calcification of each freely mobile nodule (thoracolith) and for the presence of coexisting abnormalities.

RESULTS

The mean age of 9 patients (5 women) was 65.8 years (SD 14.9; range 37-83 years). Eight were > 50 years of age. Three patients had two thoracoliths, and the remaining 6 patients had one. Thoracoliths were in the left (n = 9) or right (n = 3) pleural cavity, with most in the lower pleural cavity. Nine thoracoliths were found to be larger at follow-up. The median diameters of the 12 thoracoliths were 4.9 mm (range 2.1-10.6 mm) and 6.2 mm (range 3.6-11.0 mm) on the initial and latest follow-up CT scans, respectively. Concomitant old granulomatous disease (n = 6) and diffuse systemic sclerosis-related interstitial lung disease (n = 2) were noted.

CONCLUSION

Thoracolithiasis can manifest as one or two small calcified nodules. It tends to occur in the left lower pleural cavity, occur in a patient aged > 50 years, be larger on follow-up, and coincide with other diseases.